Solid-state imaging device and manufacturing method

ABSTRACT

There is provided a solid-state imaging device including an imaging unit including a plurality of image sensors, and an analog to digital (AD) conversion unit including a plurality of AD converters arranged in a row direction, each AD converter performing AD conversion of an electrical signal output by the image sensor. Each of the AD converters includes a comparator having a differential pair at an input stage, the differential pair including a first transistor and a second transistor, the first and second transistors are each divided into an equal number of a plurality of division transistors, and an arrangement pattern of the plurality of division transistors constituting the comparator in a predetermined column and an arrangement pattern of the plurality of division transistors constituting the comparator in an adjacent column adjacent to the predetermined column are different from each other.

BACKGROUND

The present technology relates to a solid-state imaging device and amanufacturing method, and more particularly, to a solid-state imagingdevice and a manufacturing method capable of improving a crosstalkcharacteristic between comparators constituting AD converters inadjacent columns without a side effect, for example, in a solid-stateimaging device such as an image sensor including a so-called columnparallel type AD conversion unit having a plurality of AD convertersarranged in a row direction.

An example of a solid-state imaging device that captures an imageincludes a CCD (Charge Coupled Device) image sensor or a CMOS(Complementary Metal Oxide Semiconductor) image sensor. In recent years,a CMOS image sensor is attracting attention due to requests forminiaturization or the like.

The CMOS image sensor includes an AD conversion unit that AD (Analog toDigital) converts an analog electrical signal output by a pixel, whichperforms photoelectric conversion. As the AD conversion unit of the CMOSimage sensor, a column parallel type AD conversion unit (hereinafteralso referred to as a column parallel AD conversion unit) capable ofperforming, in parallel, AD conversion on electrical signals output bytwo or more pixels such as all of a plurality of pixels arranged in onerow output is adopted from a request of high-speed processing or thelike (Japanese Patent No. 4470700).

The column parallel AD conversion unit is configured, for example, byarranging a plurality of ADCs (AD Converters) the number of which isequal to the number of columns of pixels, side by side in a rowdirection, and the ADC in each column performs AD conversion of theelectrical signal output by the pixel in the column.

An example of the ADC constituting the column parallel AD conversionunit includes a so-called reference signal comparison-type ADC thatincludes a comparator and a counter and performs AD conversion of anelectrical signal output by the pixel by comparing a predeterminedreference signal with the electrical signal.

An example of the reference signal comparison type ADC includes asingle-slope ADC.

In the single-slope ADC, an electrical signal output by a pixel isAD-converted by a comparator comparing a reference signal whose level ischanged at a constant slope, such as a ramp signal, with the electricalsignal output by the pixel, and a counter counting a time necessary fora change of the level of the reference signal until the levels of thereference signal and the electrical signal match (Japanese Patent No.4470700).

SUMMARY

One important performance index of a column parallel AD conversion unitin which a plurality of ADCs are arranged in a row includes a crosstalkcharacteristic. In the column parallel AD conversion unit, a crosstalkcharacteristic between comparators constituting the ADCs (between acomparator of an ADC in any column and a comparator of an ADC in acolumn adjacent to the column) (substantially) governs a crosstalkcharacteristic of the entire column parallel AD conversion unit.

One factor that deteriorates a crosstalk characteristic between thecomparators constituting the ADCs is a parasitic capacitance couplingthe two comparators of the ADCs in adjacent columns, which is createdbetween the two comparators.

In a CMOS image sensor, deterioration of the crosstalk characteristicbetween the comparators constituting the ADCs and thus the crosstalkcharacteristic of the column parallel AD conversion unit leads todegradation of image quality, such as color mixture, blur of light andshade, or increase in an influence of a defect pixel of an imagecaptured by the CMOS image sensor.

Further, recently, according to a request for reduction of a size ofpixels of the CMOS image sensor, a column pitch, i.e., a distancebetween columns of the adjacent ADCs, tends to be further decreased(shorter).

Further, in a stack type image sensor in which mounting is performed tostack a pixel chip that is a bare chip including pixels on the upperside and a circuit chip that is a bare chip including circuits otherthan the pixels, including a column parallel AD conversion unit, on thelower side, it is necessary to form the circuit chip to have(substantially) the same size as the pixel chip for miniaturization.

In this case, since it is necessary for various circuits as well as thecolumn parallel AD conversion unit to be formed in the circuit chip, itis necessary for the column pitch of the ADCs of the column parallel ADconversion unit to be smaller than the column pitch of the pixel.

Further, when the column pitch of the ADC is smaller, a distance betweentwo comparators of the ADCs in adjacent columns becomes smaller. As aresult, the parasitic capacitance between the two comparators of theADCs in the adjacent columns increases and the crosstalk characteristicalso deteriorates.

An example of a method of improving the crosstalk characteristic of thecolumn parallel AD conversion unit includes a method of providing astrong shield between ADCs in adjacent columns or a method of increasinga distance between comparators (of ADCs) in adjacent columns byphysically forming transistors constituting the comparator of the ADC ineach column to be elongated in a column direction.

However, in the method of providing the shield between ADCs in theadjacent columns, a side effect occurs in that an area of the columnparallel AD conversion unit increases as much as the shield is provided.

Further, in the method of forming the transistors constituting thecomparator to be elongated, since a proportion of an interfaceincreases, a parasitic capacitance relative to ground increases.Accordingly, a side effect occurs in that a noise characteristic isdegraded or a noise called a process-caused noise such as RTS (RandomTelegraph Signal) noise increases.

This technology has been made in view of such circumstances and isintended to improve a crosstalk characteristic without a side effect.

According to an embodiment of the present technology, there is provideda solid-state imaging device including an imaging unit including aplurality of image sensors, and an analog to digital (AD) conversionunit including a plurality of AD converters arranged in a row direction,each AD converter performing AD conversion of an electrical signaloutput by the image sensor. Each of the AD converters includes acomparator having a differential pair at an input stage, thedifferential pair including a first transistor and a second transistor,the first and second transistors are each divided into an equal numberof a plurality of division transistors, and an arrangement pattern ofthe plurality of division transistors constituting the comparator in apredetermined column and an arrangement pattern of the plurality ofdivision transistors constituting the comparator in an adjacent columnadjacent to the predetermined column are different from each other.

In the solid-state imaging device as described above, the AD conversionunit having a plurality of AD converters arranged in a row directionincludes a comparator having a differential pair at an input stage, thedifferential pair including a first transistor and a second transistor,and the first and second transistors are divided into the same number ofa plurality of division transistors. The arrangement pattern of theplurality of division transistors constituting the comparator in apredetermined column and the arrangement pattern of the plurality ofdivision transistors constituting the comparator in an adjacent columnadjacent to the predetermined column are different from each other.

According to an embodiment of the present technology, there is provideda method of manufacturing a solid-state imaging device including animaging unit including a plurality of image sensors, and an analog todigital (AD) conversion unit including a plurality of AD convertersarranged in a row direction, each AD converter performing AD conversionof an electrical signal output by the image sensor, the method includingincluding, in each of the AD converters, a comparator having adifferential pair at an input stage, the differential pair including afirst transistor and a second transistor, dividing the first and secondtransistors each into an equal number of a plurality of divisiontransistors, and arranging the plurality of division transistorsconstituting the comparator in a predetermined column and the pluralityof division transistors constituting the comparator in an adjacentcolumn adjacent to the predetermined column in different arrangementpatterns.

In the manufacturing method as described above, the plurality ofdivision transistors constituting the comparator in a predeterminedcolumn and the plurality of division transistors constituting thecomparator in an adjacent column adjacent to the predetermined columnare arranged in a different arrangement pattern.

Further, the solid-state imaging device may be an independent device ormay be an internal block constituting one device.

According to an embodiment of the present technology, it is possible toimprove a crosstalk characteristic. Particularly, in the solid-stateimaging device including the AD conversion unit having a plurality of ADconverters arranged in a row direction, it is possible to improve acrosstalk characteristic between the comparators constituting the ADconverters in the adjacent columns without a side effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a configuration example of anembodiment of a digital camera to which the present technology has beenapplied;

FIG. 2 is a block diagram illustrating a configuration example of animage sensor 2;

FIG. 3 is a circuit diagram illustrating a configuration example of apixel 11 _(m,n);

FIG. 4 is a block diagram illustrating a configuration example of an ADC31 _(n);

FIG. 5 is a circuit diagram illustrating a configuration example of acomparator 61 _(n);

FIG. 6 is a diagram illustrating mounting of the image sensor 2 on asemiconductor chip (a paired chip);

FIG. 7 is a circuit diagram illustrating a configuration example of adifferential pair of the comparator 61 _(n) when FET#A_(n) and FET#B_(n)are divided into two FET#A1 _(n) and FET#A2 _(n) and two FET#B1 _(n) andFET#B2 _(n), respectively;

FIG. 8 is a diagram illustrating an example of an arrangement in acolumn area of FET#A1 _(n) and FET#A2 _(n) into which FET#A_(n) has beendivided and FET#B1 _(n) and FET#B2 _(n) into which FET#B_(n) has beendivided;

FIG. 9 is a circuit diagram illustrating a differential pair of acomparator 61 _(n−1) in an (n−1)^(th) column and a differential pair ofa comparator 61 _(n) in an n^(th) column that are adjacent to eachother, in which parasitic capacitances are created;

FIG. 10 is a diagram illustrating a first example of an arrangement ofFET#A_(n) and FET#B_(n) improving a crosstalk characteristic;

FIG. 11 is a circuit diagram illustrating a differential pair of acomparator 61 _(n−1) in an (n−1)^(th) column and a differential pair ofa comparator 61 _(n) in an n^(th) column that are adjacent to eachother, in which parasitic capacitances are created;

FIG. 12 is a circuit diagram illustrating a differential pair of acomparator 61 _(n−1) in an (n−1)^(th) column and a differential pair ofa comparator 61 _(n) in an n^(th) column that are adjacent to eachother, in which parasitic capacitances are created;

FIG. 13 is a diagram illustrating a second example of an arrangement ofFET#A_(n) and FET#B_(n) improving a crosstalk characteristic;

FIG. 14 is a circuit diagram illustrating a differential pair of acomparator 61 _(n−1) in an (n−1)^(th) column and a differential pair ofa comparator 61 _(n) in an n^(th) column that are adjacent to eachother, in which parasitic capacitances are created;

FIG. 15 is a diagram illustrating a third example of an arrangement ofFET#A_(n) and FET#B_(n) improving a crosstalk characteristic;

FIG. 16 is a circuit diagram illustrating a differential pair of acomparator 61 _(n−1) in an (n−1)^(th) column and a differential pair ofa comparator 61 _(n) in an n^(th) column that are adjacent to eachother, in which parasitic capacitances are created;

FIG. 17 is a diagram illustrating a fourth example of an arrangement ofFET#A_(n) and FET#B_(n) improving a crosstalk characteristic;

FIG. 18 is a circuit diagram illustrating a differential pair of acomparator 64 _(n−1) in an (n−1)^(th) column and a differential pair ofa comparator 61 _(n) in an n^(th) column that are adjacent to eachother, in which parasitic capacitances are created;

FIG. 19 is an overview diagram illustrating a configuration example whenthe image sensor 2 is configured as a semiconductor chip; and

FIG. 20 is a flowchart illustrating a method of manufacturing asemiconductor chip as the image sensor 2.

DETAILED DESCRIPTION OF THE EMBODIMENT(S)

Hereinafter, preferred embodiments of the present disclosure will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

[Embodiment of a Digital Camera to which the Present Technology has beenApplied]

FIG. 1 is a block diagram illustrating a configuration example of anembodiment of a digital camera to which the present technology has beenapplied.

Further, the digital camera can capture either a still image or a movingimage.

In FIG. 1, the digital camera includes an optical system 1, an imagesensor 2, a memory 3, a signal processing unit 4, an output unit 5, anda control unit 6.

For example, the optical system 1 includes a zoom lens, a focus lens, aniris and the like, which are not illustrated, and causes light from theoutside to be incident on the image sensor 2.

The image sensor 2 is, for example, a CMOS image sensor, and receivesincident light from the optical system 1, performs photoelectricconversion, and outputs image data corresponding to the incident lightfrom the optical system 1.

The memory 3 temporarily stores the image data output by the imagesensor 2.

The signal processing unit 4 performs, for example, a process such asremoval of noise or adjustment of white balance as signal processingusing the image data stored in the memory 3, and supplies resultantimage data to the output unit 5.

The output unit 5 outputs the image data from the signal processing unit4.

In other words, the output unit 5 includes, for example, a display (notillustrated) including liquid crystal or the like, and displays an imagecorresponding to the image data from the signal processing unit 4 as aso-called through image.

Further, the output unit 5 includes, for example, a driver (notillustrated) that drives a recording medium such as a semiconductormemory, a magnetic disk, or an optical disc, and records the image datafrom the signal processing unit 4 in the recording medium.

The control unit 6 controls each block constituting the digital cameraaccording to a manipulation of a user or the like.

In the digital camera configured as described above, the image sensor 2receives the incident light from the optical system 1 and outputs theimage data according to the incident light.

The image data output by the image sensor 2 is supplied to and stored inthe memory 3.

The signal processing unit 4 performs signal processing of the imagedata stored in the memory 3, and supplies the image data to the outputunit 5.

In the output unit 5, the image data from the signal processing unit 4is output.

[Configuration Example of Image Sensor 2]

FIG. 2 is a block diagram illustrating a configuration example of theimage sensor 2 of FIG. 1.

In FIG. 2, the image sensor 2 includes a pixel array 10, a pixel drivingunit 21, a column parallel AD conversion unit 22, and an output unit 23.

The pixel array 10 is an imaging unit including M×N (M and N areintegers equal to or more than 1) pixels 11 _(1,1), 11 _(1,2), . . . ,11 _(1,N), 11 _(2,1), 11 _(2,2), 11 _(2,N), . . . , 11 _(M,1), 11_(M,2), . . . , 11 _(M,N) as image sensors that perform capturing.

The M×N pixels 11 _(1,1) to 11 _(M,N) are arranged in a matrix (lattice)of M rows and N columns on a two-dimensional plane.

Here, in the present embodiment, the number N of columns is plural, andtherefore, at least a plurality (N) of pixels 11 _(m,1), 11 _(m,2), . .. 11 _(m,N) are arranged in a row direction in the pixel array 10.

A pixel control line 41 _(m) extending in the row direction (horizontaldirection) is connected to the N pixels 11 _(m,1) to 11 _(m,N) arrangedin the row direction of the m^(th) row (m=1, 2, . . . , M) (from thetop) in the pixel array 10.

Further, a vertical signal line 42 _(n) extending in the columndirection (vertical direction) is connected to M pixels 11 _(1,n) to 11_(M,n) arranged in the column direction of the n^(th) column (n=1,2, . .. , N) (from the left).

The pixel 11 _(m,n) performs photoelectric conversion of light incidenton the pixel 11 _(m,n) (incident light). Furthermore, the pixel 11_(m,n) outputs a voltage (an electrical signal) corresponding toelectric charges obtained through the photoelectric conversion onto thevertical signal line 42 _(n) according to control from the pixel drivingunit 21 via the pixel control line 41 _(m).

Further, the pixel 11 _(m,n) may perform, for example, photoelectricconversion of a predetermined color of light that is incident via acolor filter (not illustrated) of a Bayer array or the like.

The pixel driving unit 21, for example, controls (drives) the pixels 11_(m,l) to 11 _(m,N) connected to the pixel control line 41 _(m), via thepixel control line 41 _(m) according to control of the control unit 6(FIG. 1) or the like.

The column parallel AD conversion unit 22 is connected with the pixels11 _(m,1) to 11 _(m,N) arranged in one row via the vertical signal lines42 ₁ to 42 _(N). Therefore, the voltage (the electrical signal) outputby the pixel 11 _(m,n) is supplied to the column parallel AD conversionunit 22 via the vertical signal line 42 _(n).

The column parallel AD conversion unit 22 performs, in parallel, ADconversion of the voltages (electrical signals) supplied from the pixels11 _(m,1) to 11 _(m,N) arranged in one row via the vertical signal lines42 ₁ to 42 _(N), and supplies resultant digital data to the output unit23 as pixel values (pixel data) of the pixels 11 _(m,1) to 11 _(m,N).

Here, the column parallel AD conversion unit 22 may perform, inparallel, the AD conversion of all the electrical signals of N pixels 11_(m,1) to 11 _(m,N) arranged in one row, as well as perform, inparallel, AD conversion of the electrical signals of a plurality ofpixels the number of which is less than N among the N pixels 11 _(m,1)to 11 _(m,N).

However, hereinafter, the column parallel AD conversion unit 22 isassumed to perform, in parallel, the AD conversion of the electricalsignals of all of N pixels 11 _(m,1) to 11 _(m,N) arranged in one row inorder to simplify the description.

The column parallel AD conversion unit 22 includes a number N of ADCs(Analog to Digital Converters) 31 ₁ to 31 _(N) to perform, in parallel,the AD conversion of the electrical signals of all the N pixels 11_(m,1) to 11 _(m,N) arranged in one row.

Further, the column parallel AD conversion unit 22 includes a referencesignal output unit 32 and a clock output unit 33.

The reference signal output unit 32 supplies (outputs), for example, areference signal whose level is changed from a predetermined initialvalue to a predetermined final value at a constant slope, such as a rampsignal, to the ADCs 31 ₁ to 31 _(N) via a reference signal line 32A.

The clock output unit 33 supplies (outputs) a clock at a predeterminedfrequency to the ADCs 31 ₁ to 31 _(N) via a clock line 33A.

The ADC 31 _(n) is connected to the vertical signal line 41 _(n), andtherefore an electrical signal of the pixel 11 _(m,n) (the electricalsignal output by the pixel 11 _(m,n)) is supplied to the ADC 31 via thevertical signal line 41 _(n).

The ADC 31 _(n) performs CDS (Correlated Double Sampling) and ADconversion of the electrical signal supplied from the pixel 11 _(m,n),via the vertical signal line 41 _(n) using the reference signal from thereference signal output unit 32 and the clock from the clock output unit33.

In other words, the ADC 31 _(n) performs the AD conversion and the CDSof the electrical signal from the pixel 11 _(m,n) by comparing theelectrical signal from the pixel 11 _(m,n) with the reference signalfrom the reference signal output unit 32 and counting a time necessaryfor a level of the reference signal to be changed until levels of theelectrical signal from the pixel 11 _(m,n) and the reference signalmatch.

Here, in the ADC 31 _(n) the count of the time necessary for the levelof the reference signal to be changed until the levels of the electricalsignal from the pixel 11 _(m,n) and the reference signal match isperformed by counting the clock from the clock output unit 33.

The ADC 31 _(n), supplies digital data that can be obtained as a resultof the AD conversion and the CDS to the output unit 23 as a pixel value(pixel data) of the pixel 11 _(m,n).

Further, the electrical signals of the N pixels 11 _(m,1) to 11 _(m,N)of each of the first row to the M^(th) row of the pixel array 10 aresupplied to the N ADCs 31 ₁ to 31 _(N), for example, sequentially fromthe first row, and the AD conversion and the CDS of the electricalsignals are performed, so to speak, in unit of rows.

The output unit 23 temporarily stores the pixel data of the pixels 11_(m,1) to 11 _(m,N) from the ADCs 31 ₁ to 31 _(N), and outputs the pixeldata as image data of the m^(th) row to the outside (in the presentembodiment, the memory 3 (FIG. 1)).

Further, while the CDS as well as the AD conversion is assumed to beperformed in the ADC 31 _(n) herein, only the AD conversion may beperformed in the ADC 31 _(n) and the CDS may be performed in the outputunit 23.

[Configuration Example of Pixel 11 _(m,n)]

FIG. 3 is a circuit diagram illustrating a configuration example of thepixel 11 _(m,n) of FIG. 2.

In FIG. 3, the pixel 11 _(m,n) includes a PD (Photodiode) 51 and fournMOS (negative channel MOS) FETs (Field Effect Transistors) 52, 54, 55and 56.

Further, in the pixel 11 _(m,n) a drain of the FET 52, a source of theFET 54 and a gate of the FET 55 are connected, and a FD (FloatingDiffusion) (capacitance) 53 for converting electric charges to a voltageis formed at a point of the connection.

The PD 51 is an example of the photoelectric conversion element as theimage sensor, and receives incident light and accumulates the electriccharges corresponding to the incident light to perform the photoelectricconversion.

An anode of the PD 51 is connected to the ground (is grounded), and acathode of the PD 51 is connected to a source of the FET.

The FET 52 is an FET for transferring electric charges accumulated inthe PD 51 from the PD 51 to the FD 53, and is hereinafter referred to asa transfer Tr 52.

The source of the transfer Tr 52 is connected to a cathode of the PD 51,and the drain of the transfer Tr 52 is connected to the source of theFET 54 via the FD 53.

Further, a gate of the transfer Tr 52 is connected to the pixel controlline 41 _(m), and a transfer pulse TRG is supplied to the gate of thetransfer Tr 52 via the pixel control line 41 _(m).

Here, since the pixel driving unit 21 (FIG. 2) drives (controls) thepixel 11 _(m,n) via the pixel control line 41 _(m), a control signalflowing in the pixel control line 41 _(m) includes a reset pulse RST anda selection pulse SEL, which will be described below, as well as thetransfer pulse TRG.

The FD 53 is an area that converts electric charges to a voltage, like acapacitor formed at the connection point of the drain of the transfer Tr52, the source of the FET 54 and the gate of the FET 55.

The FET 54 is an FET for resetting the electric charges (voltage;electric potential) accumulated in the FD 53, and is hereinafterreferred to as a reset Tr 54.

A drain of the reset Tr 54 is connected to a power supply Vdd.

Further, the gate of the reset Tr 54 is connected to the pixel controlline 41 _(m), and the reset pulse RST is supplied to the gate of thereset Tr 54 via the pixel control line 41 _(m).

The FET 55 is an FET for amplifying the voltage of the FD 53, and ishereinafter referred to as an amplification Tr 55.

The gate of the amplification Tr 55 is connected to the FD 53, and adrain of the amplification Tr 55 is connected to the power supply Vdd.Further, a source of the amplification Tr 55 is connected to a drain ofthe FET 56.

The FET 56 is an FET for selecting the output of the electrical signal(the voltage) to the vertical signal line 42 _(n), and is hereinafterreferred to as a selection Tr 56.

A source of the selection Tr 56 is connected to the vertical signal line42.

Further, the gate of the selection Tr 56 is connected to the pixelcontrol line 41 _(m), and the selection pulse SEL is supplied to thegate of the selection Tr 56 via the pixel control line 41 _(m).

Here, the pixel 11 _(m,n) may be configured without the selection Tr 56.

Further, a configuration of a shared pixel in which a plurality of PDs51 and transfer Trs 52 share the FD 53 to the selection Tr 56 may beadopted as a configuration of the pixel 11 _(m,n).

In the pixel 11 _(m,n) configured as above, the PD 51 startsaccumulation of the electric charges according to an amount of incidentlight by receiving the incident light and performing the photoelectricconversion.

When a predetermined time (exposure time) has elapsed after theaccumulation of the electric charges in the PD 51 has started, the pixeldriving unit 21 (FIG. 2) temporarily sets the transfer pulse TRG to an H(High) level (from an L (Low) level).

As the transfer pulse TRG is temporarily at the H level, the Transfer Tr52 is temporarily in an ON state.

When the transfer Tr 52 enters the ON state, the electric chargesaccumulated in the PD 51 are transferred to the FD 53 via the transferTr 52 and accumulated.

Here, before temporarily setting the transfer pulse TRG to the H level,the pixel driving unit 21 temporarily sets the reset pulse RST to the Hlevel to thereby temporarily set the reset Tr 54 to an ON state.

As the reset Tr 54 is in the ON state, the electric charges in the FD 53are swept out to the power supply Vdd via the reset Tr 54 and reset.

After the electric charges of the FD 53 are reset, the pixel drivingunit 21 temporarily sets the transfer pulse TRG to the H level tothereby temporarily set the transfer Tr 52 to an ON state, as describedabove.

As the transfer Tr 52 enters the ON state, the electric chargesaccumulated in the PD 51 are transferred to the reset FD 53 via thetransfer Tr 52 and accumulated.

Meanwhile, the amplification Tr 55 outputs, to its source, the voltage(electric potential) corresponding to the electric charges in the FD 53connected to the gate.

As described above, the source of the amplification Tr 55 is connectedto the drain of the selection Tr 56. When the selection Tr 56 enters anON state, the selection Tr 56 outputs the voltage output (appearing) inthe source of the amplification Tr 55 to the vertical signal line 42connected to the source of the selection Tr 56 to be supplied to the ADC31 _(n) (FIG. 2) connected to the vertical signal line 42 _(n).

The pixel driving unit 21 temporarily sets the selection pulse SEL tothe H level at a timing immediately after the FD 53 (electric charges inthe FD 53) is reset as the reset Tr 54 enters the ON state and a timingafter the electric charges accumulated in the PD 51 are transferred toand accumulated in the reset FD 53 via the transfer Tr 52 as thetransfer Tr 52 enters the ON state.

As the selection pulse SEL is temporarily at an H level at the timingimmediately after the FD 53 is reset, the selection Tr 56 enters the ONstate, and the voltage of the reset FD 53 (hereinafter referred to as areset level) is supplied to the ADC 31 _(n) connected to the verticalsignal line 42 _(n) via the amplification Tr 55, and the selection Tr 56that is in an ON state.

Further, as the selection pulse SEL is temporarily at an H level at atiming after the electric charges accumulated in the PD 51 aretransferred to and accumulated in the reset FD 53, the selection Tr 56enters the ON state, and the voltage of the FD 53 after the electriccharges have been transferred from the PD 51, i.e., a voltage (referredto as a signal level) corresponding to the pixel data (a pixel value)relative to the reset level is supplied to the ADC 34 connected to thevertical signal line 42 _(n) via the amplification Tr 55, and theselection Tr 56 that is in the ON state.

In the ADC 31 _(n), AD conversion of the signal level and the resetlevel, and CDS of subtracting the reset level from the signal level andextracting the voltage (electrical signal) corresponding to the electriccharges accumulated in the PD 51 as the pixel data are performed.

[Configuration Example of ADC 31 _(n)]

FIG. 4 is a block diagram illustrating a configuration example of theADC 31 _(n) of FIG. 2.

The ADC 31 _(n) includes a comparator 61 _(n) and a counter 62 _(n), andperforms reference signal comparison type ADC, and CDS.

One of the reference signal from the reference signal output unit 32 andthe electrical signal (the reset level or the signal level) from thepixel 11 _(m,n), for example, the reference signal, is supplied to aninversion input terminal (−) that is one of two input terminals of thecomparator 61 _(n). The other of the reference signal from the referencesignal output unit 32 and the electrical signals from the pixel 11_(m,n), for example, the electrical signal, is supplied to anon-inversion input terminal (+) as the other of the two input terminalsof the comparator 61 _(n).

The comparator 61 _(n) compares the reference signal supplied to theinversion input terminal with the electrical signal supplied to thenon-inversion input terminal. Further, the comparator 61 _(n) outputsone of H and L levels, for example, an H level, when the referencesignal supplied to the inversion input terminal is higher than thevoltage of the electrical signal supplied to the non-inversion inputterminal.

Further, when the electrical signal supplied to the non-inversion inputterminal is equal to or higher than the voltage of the reference signalsupplied to the inversion input terminal (when the reference signalsupplied to the inversion input terminal is equal to or lower than thevoltage of the electrical signal supplied to the non-inversion inputterminal), the comparator 61 _(n) outputs the other of the H level andthe L level, i.e., the L level.

The output of the comparator 61 _(n) and the clock from the clock outputunit 33 are supplied to the counter 62 _(n).

When the reference signal output unit 32 supplies an initial value ofthe reference signal to the comparator 61 _(n), the counter 62 _(n)starts count of the clock from the clock output unit 33. For example,when the output of the comparator 61 _(n) is changed from an H level toan L level, in other words, when the levels of the reference signalsupplied to the inversion input terminal of the comparator 61 and theelectrical signal supplied to the non-inversion input terminal areequal, the counter 62 ends the count of the clock from the clock outputunit 33.

Further, the counter 62 outputs a count value of the clock as an ADconversion result of the electrical signal supplied to the non-inversioninput terminal of the comparator 61 _(n).

Here, the reference signal output unit 32, for example, outputs a rampsignal reduced at a certain rate from a predetermined initial value(e.g., a value equal to or more than a maximum value of the electricalsignal output by the pixel 11 _(m,n)) to a predetermined final value(e.g., a value equal to or less than a minimum value of the electricalsignal output by the pixel 11 _(m,n)) as the reference signal.

In this case, in the counter 62 _(n), the count value of the clock as atime until the ramp signal as the reference signal is changed from apredetermined initial value to the voltage (or less) of the electricalsignal supplied to the non-inversion input terminal of the comparator 61is counted and becomes the AD conversion result of the electrical signalsupplied to the non-inversion input terminal of the comparator 61 _(n).

When the ADC 31 _(n) obtains the AD conversion result of the reset leveland the signal level as the electrical signal supplied from the pixel 11_(m,n) to the non-inversion input terminal of the comparator 61 _(n),the ADC 31 _(n) performs CDS by subtracting the AD conversion result ofthe reset level from the AD conversion result of the signal level andoutputs a resultant subtraction level as the pixel data (pixel value) ofthe pixel 11 _(m,n).

Further, the ADC 31 _(n) may perform CDS, for example, by controllingthe count of the clock in the counter 62 _(n), instead of performing CDSby actually performing an operation of subtracting the AD conversionresult of the reset level from the AD conversion result of the signallevel.

In other words, the counter 62 _(n) may perform the CDS of subtractingthe reset level from the signal level while performing the AD conversionof the reset level and the signal level, for example, by counting theclock while decrementing the count value by 1 for the reset level andcounting the clock while incrementing the count value by 1 for thesignal level using the count value of the clock for the reset level asan initial value.

[Configuration Example of the Comparator 61 _(n)]

FIG. 5 is a circuit diagram illustrating a configuration example of thecomparator 61 _(n) in FIG. 4.

In FIG. 5, the comparator 61 _(n) includes FET#A_(n), FET#B_(n),FET#C_(n), FET#D_(n), and a current source I_(n).

FET#A_(n) and FET#B_(n) are NMOS (Negative Channel MOS) FETs, andsources of FET#A_(n) and FET#B_(n) are connected to each other. Further,a connection point between the sources of FET#A_(n) and FET#B_(n) isconnected to the other terminal of the current source I_(n), one end ofwhich is grounded. FET#A_(n) and FET#B_(n) constitute a so-calleddifferential pair.

A gate of FET#A_(n) is connected to the inversion input terminal IN1_(n) of the comparator 61 _(n), and a gate of FET#B_(n) is connected tothe non-inversion input terminal IN2 _(n) of the comparator 61 _(n).

Thus, the comparator 61 _(n) includes the differential pair includingFET#A_(n) and FET#B_(n) at an input stage.

Here, one of FET#A_(n) and FET#B_(n) constituting the differential pairof the comparator 61 _(n), for example, FET#A_(n), is referred to as afirst transistor, and the other FET#B_(n) is referred to as a secondtransistor.

FET#C_(n) and FET#D_(n) are PMOS (Positive Channel MOS) FETs, and gatesof FET#C_(n) and FET#D_(n) are connected to each other.

Further, sources of FET#C_(n) and FET#D_(n) are connected to a powersupply Vdd, and a connection point between the gates of FET#C_(n) andFET#D_(n) is connected to a drain of FET#C_(n). Therefore, FET#C_(n) andFET#D_(n) constitute a current minor.

Among FET#C_(n) and FET#D_(n) constituting the current minor asdescribed above, a drain of FET#C_(n) is connected to a drain ofFET#A_(n), and a drain of FET#D_(n) is connected to a drain ofFET#B_(n).

Further, a connection point between the drains of FET#B_(n) andFET#D_(n) is connected to an output terminal OUT_(n) of the comparator61 _(n).

Further, a circuit for performing desired output from the comparator 61_(n) is provided between the connection point between the drains ofFET#B_(n) and FET#D_(n) and the output terminal OUT_(n), but anillustration of the circuit is omitted herein.

In the comparator 61 _(n) configured as above, when a voltage of theinversion input terminal IN1 _(n) is higher than a voltage of thenon-inversion input terminal IN2 _(n), roughly, FET#A_(n) is turned onand FET#B_(n) is turned off. As FET#A_(n) is turned on, FET#C_(n) andthus FET#D_(n) are turned on and current flows from the power supply Vddto the output terminal OUT_(n) via FET#D_(n). Accordingly, the outputterminal OUT_(n) is at an H level.

On the other hand, when the voltage of the non-inversion input terminalIN2 _(n) is higher than the voltage of the inversion input terminal IN1_(n), roughly, FET#A_(n) is turned off and FET#B_(n) is turned on. AsFET#A_(n) is turned off, FET#C_(n) and FET#D_(n) are turned off andcurrent is drawn from the output terminal OUT_(n) to the current sourceI_(n) via FET#B_(n). Accordingly, the output terminal OUT_(n) is at an Llevel.

Further, while the comparator 61 _(n) is configured using FETs in FIG.5, the comparator 61 _(n) may be configured of, for example, bipolartransistors or the like.

[Mounting of Image Sensor 2 on Semiconductor Chip]

FIG. 6 is a diagram illustrating mounting of the image sensor 2 of FIG.2 on a semiconductor chip (paired chips).

In the image sensor 2 of FIG. 2, the N ADCs 31 ₁ to 31 _(N) included inthe column parallel AD conversion unit 22 are arranged (formed) side byside in the row direction on a semiconductor chip, for example, in orderto perform, in parallel, AD conversions of electrical signals of all theN pixels 11 _(m,1) to 11 _(m,N) arranged in one row.

Further, an area of the semiconductor chip in which the column parallelAD conversion unit 22 is arranged (formed) is limited due to a requestfor miniaturization of the CMOS image sensor 2, and an area of thesemiconductor chip in which the N ADCs 31 ₁ to 31 _(N) included in thecolumn parallel AD conversion unit 22 are arranged is also limited.

Particularly, for N ADCs 31 ₁ to 31 _(N) arranged side by side in therow direction, a width (a length in the row direction) L of one columnin which one ADC 31 _(n) is arranged is limited by the number N ofpixels (in the horizontal direction) per row or the like.

For example, now, a rectangular area on the semiconductor chip isassigned to arrange one ADC 31 _(n). The rectangular area is referred toas a column area.

When the width L of the column area is limited, FET#A_(n) and FET#B_(n)having a desired specification, which constitute the differential pairof the comparator 61 _(n) (FIG. 5) of the ADC 31 _(n), may not bearranged in the column area directly (with their sizes).

In other words, when any one of a horizontal W and a vertical H ofFET#A_(n) and FET#B_(n) having a desired specification is greater thanthe width L of the column area as illustrated in FIG. 6, it is difficultto directly arrange FET#A_(n) and FET#B_(n) in the column area.

Accordingly, FET#A_(n) and FET#B_(n) are divided into the same number ofa plurality of division transistors having a small size to be arrangedin the column area, and are arranged in the column area, as illustratedin FIG. 6.

Here, in FIG. 6, FET#A_(n) is divided into two FETs, FET#A1 _(n) andFET#A2 _(n) as a plurality of division transistors having the same size,which then are arranged in the column area.

FET#B_(n) is also divided into two FET#B1 _(n) and FET#B2 _(n) havingthe same size and arranged in the column area, like FET#A_(n).

Further, in FIG. 6, FET#A1 _(n), FET#A2 _(n), FET#B1 _(n) and FET#B2_(n) are arranged in this order from a bottom in the column area.

FIG. 7 is a circuit diagram illustrating a configuration example of thedifferential pair of the comparator 61 _(n) when FET#A_(n) and FET#B_(n)are divided into two FET#A1 _(n) and FET#A2 _(n) and two FET#B1 _(n) andFET#B2 _(n), respectively, as illustrated in FIG. 6.

Further, in the drawings below, in order to assist in understanding,FET#A_(n) as the first transistor and FETs into which FET#A_(n) has beendivided are illustrated by a solid line, and FET#B_(n) as the secondtransistor and FETs into which FET#B_(n) has been divided areillustrated by a dotted line.

FET#A1 _(n) and FET#A2 _(n) into which FET#A_(n) has been divided areconnected in parallel.

In other words, in FET#A1 _(n) and FET#A2 _(n) into which FET#A_(n) hasbeen divided, gates of FET#A1 _(n) and FET#A2 _(n) are connected to eachother, drains thereof are connected to each other, and sources thereofare connected to each other.

FET#B1 _(n) and FET#B2 _(n) into which FET#B_(n) has been divided arealso connected in parallel, like FET#A1 _(n) and FET#A2 _(n).

FIG. 8 is a diagram illustrating an example of an arrangement of FET#A1_(n) and FET#A2 _(n) into which FET#A_(n) has been divided and FET#B1_(n) and FET#B2 _(n) into which FET#B_(n) has been divided, in thecolumn area.

In FIG. 8, an arrangement of three columns of FET#A1 _(n−1), FET#A2_(n−1), FET#B1 _(n−1) and FET#B2 _(n−1) of the (n−1)^(th) column (FET#A1_(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2 _(n−1) arranged in thecolumn area in which ADC 31 _(n−1) is formed), FET#A1 _(n), FET#A2 _(n),FET#B1 _(n) and FET#B2 _(n) of the n^(th) column, and FET#A1_(n+1)/FET#A2 _(n+1), FET#B1 _(n+1) and FET#B2 _(n+1) of the (n+1)^(th)column is illustrated (the same applies to FIGS. 10, 13, 15 and 17 thatwill be described below).

In the n^(th) column, FET#A1 _(n), FET#A2 _(n), FET#B1 _(n) and FET#B2_(n) are arranged in this order from a bottom as illustrated in FIG. 6.The same applies to the other columns.

In other words, in FIG. 8, an arrangement pattern of FET#A1 _(n), FET#A2_(n), FET#B1 _(n) and FET#B2 _(n) of any n^(th) column is the same as anarrangement pattern of FET#A1 _(n)′, FET#A2 _(n)′, FET#B1 _(n)′ andFET#B2 _(n)′ of any other n′^(th) column.

Accordingly, in the two adjacent columns, for example, the (n−1)^(th)and n^(th) columns, FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1_(n) of the n^(th) column face each other, and FET#A2 _(n−1) of the(n−1)^(th) column and FET#A2 _(n) of the n^(th) column face each other.Further, FET#B1 _(n−1) of the (n−1)^(th) column and FET#B1 _(n) of then^(th) column face each other, and FET#B2 _(n−1) of the (n−1)^(th)column and FET#B2 _(n) of the n^(th) column face each other.

Here, FET#A1 _(n) and FET#A2 _(n) into which FET#A_(n) as the firsttransistor constituting the differential pair has been divided arereferred to as first division FETs, and FET#B1 _(n) and FET#B2 _(n) intowhich FET#B_(n) as the second transistor has been divided are referredto as second division FETs. In FIG. 8, in the (n−1)^(th) and n^(th)columns, the first division FET of the (n−1)^(th) column and the firstdivision FET of the n^(th) column face each other, and the seconddivision FET of the (n−1)^(th) column and the second division FET of then^(th) column face each other.

A column pitch (a distance between the adjacent (n−1)^(th) and n^(th)columns) is small due to the request for miniaturization of the CMOSimage sensor 2, and therefore, in the (n−1)^(th) and n^(th) columns, aparasitic capacitance coupling the facing FETs is created between thefacing FETs.

In FIG. 8, the parasitic capacitance C#A1 _(n−1) is created betweenFET#A1 _(n−1) of the (n−1)^(th) column and FET#A1 _(n) of the n^(th)column that face each other. Similarly, a parasitic capacitance C#A2_(n−1) is created between FET#A2 _(n−1) of the (n−1)^(th) column andFET#A2 _(n) of the n^(th) column that face each other, a parasiticcapacitance C#B1 _(n−1) is created between FET#B1 _(n−1) of the(n−1)^(th) column and FET#B1 _(n) of the n^(th) column that face eachother, and a parasitic capacitance C#B2 _(n−1) is created between FET#B2_(n−1) of the (n−1)^(th) column and FET#B2 _(n) of the n^(th) columnthat face each other.

Further, since a distance between FET#A1 _(n−1) of the (n−1)^(th) columnand FET#A1 _(n) of the n^(th) column that face each other, a distancebetween FET#A2 _(n−1) of the (n−1)^(th) column and FET#A2 _(n) of then^(th) column that face each other, a distance between FET#B1 _(n−1) ofthe (n−1)^(th) column and FET#B1 _(n) of the n^(th) column that faceeach other, and a distance between FET#B2 _(n−1) of the (n−1)^(th)column and FET#B2 _(n) of the n^(th) column that face each other areequal and FET#A1 _(n−1), FET#A2 _(n−1), FET#A1 _(n) and FET#A2 _(n) havethe same size, the parasitic capacitances C#A1 _(n−1), C#A2 _(n−1), C#Bl_(n−1) and C#B2 _(n−1) have (substantially) the same value.

FIG. 9 is a circuit diagram illustrating the differential pair of thecomparator 61 _(n−1) of the (n−1)^(th) column and the differential pairof the comparator 61 _(n) of the n^(th) column that are adjacent to eachother, in which parasitic capacitances are created as illustrated inFIG. 8.

As illustrated in FIG. 9, the inversion input terminal IN1 _(n−1)(connected to the gates of FET#A1 _(n−1) and FET#A2 _(n−1)) of thecomparator 64 _(—1) of the (n−1)^(th) column and the inversion inputterminal IN1 _(n) (connected to the gates of FET#A1 _(n) and FET#A2_(n)) of the comparator 61 _(n) of the n^(th) column, which areadjacent, are connected by the parasitic capacitances C#A1 _(n−1) andC#A2 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) (connected to thegates of FET#B1 _(n−1) and FET#B2 _(n−1)) of the comparator 61 _(n−1) ofthe (n−1)^(th) column and the non-inversion input terminal IN2 _(n)(connected to the gates of FET#B1 _(n) and FET#B2 _(n)) of thecomparator 61 _(n) of the n^(th) column, which are adjacent, areconnected by the parasitic capacitances C#B1 _(n−1) and C#B2 _(n−1).

Accordingly, for example, if voltage fluctuation occurs in the inversioninput terminal IN1 _(n−1) of the comparator 61 _(n−1) of the (n−1)^(th)column due to noise or the like, the voltage fluctuation influences theinversion input terminal IN1 _(n) of the comparator 61 _(n) of then^(th) column adjacent to the (n−1)^(th) column via the parasiticcapacitances C#A1 _(n−1) and C#A2 _(n−1) and, as a result, fluctuates anoutput (a voltage of the output terminal OUT_(n)) of the comparator 61_(n) of the n^(th) column.

Similarly, for example, when voltage fluctuation occurs in thenon-inversion input terminal IN2 _(n−1) of the comparator 64 _(n−1) ofthe (n−1)^(th) column due to noise or the like, the voltage fluctuationinfluences the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column adjacent to the (n−1)^(th) column via theparasitic capacitances C#B1 _(n−1), and C#B2 _(n−1), and, as a result,fluctuates the output of the comparator 61 _(n) of the n^(th) column.

Further, the voltage fluctuation of the inversion input terminal IN1_(n) or the non-inversion input terminal IN2 _(n) of the comparator 61_(n) of the n^(th) column influences the inversion input terminal IN1_(n+1) or the non-inversion input terminal IN2 _(n+1) of the comparator61 _(n+1) of the (n+1)^(th) column via parasitic capacitances betweenthe n^(th) column and the (n+1)^(th) column, like the voltagefluctuation of the inversion input terminal IN1 _(n−1), and thenon-inversion input terminal IN2 _(n−1), of the comparator 61 _(n−1) ofthe (n−1)^(th) column.

Thus, the voltage fluctuation of the inversion input terminal IN1 _(n−1)or the non-inversion input terminal IN2 _(n−1), of the comparator 61_(n−1) of the (n−1)^(th) column influences the inversion input terminalIN1 _(n) and the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column adjacent to the (n−1)^(th) column, as wellas the inversion input terminal IN1 _(n+1), or the non-inversion inputterminal IN2 _(n+1) of the comparator 61 _(n+1) of the (n+1)^(th) columnvia the parasitic capacitances between the n^(th) column and the(n+1)^(th) column.

Hereinafter, similarly, the voltage fluctuation of the inversion inputterminal IN1 _(n−1) and the non-inversion input terminal IN2 _(n−1) ofthe comparator 61 _(n−1) of the (n−1)^(th) column propagates to othercolumns in a chain reaction via the parasitic capacitances, whichdeteriorates a crosstalk characteristic of the column parallel ADconversion unit 22.

When the arrangement pattern of FET#A1 _(n), FET#A2 _(n), FET#B1 _(n)and FET#B2 _(n) of any n^(th) column and the arrangement pattern ofFET#A1 _(n)′, FET#A2 _(n)′, FET#B1 _(n)′ and FET#B2 _(n)′ of any othern′^(th) column are the same as illustrated in FIG. 8, the voltagefluctuation of the inversion input terminal IN1 _(n) or thenon-inversion input terminal IN2 _(n) of the comparator 61 _(n) of anyn^(th) column propagates to other columns via the parasitic capacitance,which deteriorates a crosstalk characteristic of the column parallel ADconversion unit 22.

[Arrangement of FET#A_(n) and FET#B_(n) Improving CrosstalkCharacteristic]

FIG. 10 is a diagram illustrating a first example of the arrangement ofFET#A_(n) and FET#B_(n) improving a crosstalk characteristic.

In FIG. 10, FET#A_(n) and FET#B_(n) are divided into FET#A1 _(n) andFET#A2 _(n) as two first division FETs and FET#B1 _(n) and FET#B2 _(n)as two second division FETs, respectively, as in the case of FIG. 8.

Further, in FIG. 10, FET#A1 _(n−1), FET#A2 _(n−1), FET#B1 _(n−1) andFET#B2 _(n−1) of any (n−1)^(th) column and FET#A1 _(n), FET#A2 _(n),FET#B1 _(n) and FET#B2 _(n) of the n^(th) column (adjacent column)adjacent to the (n−1)^(th) column are arranged so that an arrangementpattern of FET#A1 _(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2 _(n−1)of the (n−1)^(th) column and an arrangement pattern of FET#A1 _(n),FET#A2 _(n), FET#B1 _(n) and FET#B2 _(n) of the n^(th) column aredifferent from each other.

In other words, in FIG. 10, the first division FETs (FET#A1 _(n−1) andFET#A2 _(n−1)) and the second division FETs (FET#B1 _(n−1) and FET#B2_(n−1)) of the (n−1)^(th) column and the first division FETs (FET#A1_(n) and FET#A2 _(n)) and the second division FETs (FET#B1 _(n) andFET#B2 _(n)) of the n^(th) column are arranged so that parasiticcapacitance coupling between FET#A_(n−1) as the first transistor of the(n−1)^(th) column and each of FET#A_(n) as the first transistor andFET#B_(n) as the second transistor of the n^(th) column (adjacentcolumn) adjacent to the (n−1)^(th) column is created and parasiticcapacitance coupling between FET#B_(n−1) as the second transistor of the(n−1)^(th) column and each of FET#A_(n) as the first transistor andFET#B_(n) as the second transistor of the n^(th) column adjacent to the(n−1)^(th) column is created.

More specifically, in the (n−1)^(th) column and the n^(th) column,FET#A1 _(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2 _(n−1) of the(n−1)^(th) column and FET#A1 _(n), FET#A2 _(n), FET#B1 _(n) and FET#B2_(n) of the n^(th) column are arranged so that all of the first numbernum11 of the first division FET of the (n−1)^(th) column and the firstdivision FET of the n^(th) column that face each other, the secondnumber num22 of the second division FET of the (n−1)^(th) column and thesecond division FET of the n^(th) column that correspond to each other,the third number num12 of the first division FET of the (n−1)^(th)column and the second division FET of the n^(th) column that face eachother, and the fourth number num21 of the second division FET of the(n−1)^(th) column and the first division FET of the n^(th) column thatface each other are equal.

Here, FET#A1 _(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2 _(n−1)being arranged in (n−5)^(th) this order from the bottom in the(n−1)^(th) column (the same applies to . . . , the column, the(n−3)^(th) column, the (n+1)^(th) column, the (n+3)^(th) column, . . . )is common to FIG. 10 and FIG. 8.

However, FIG. 10 is different from FIG. 8 in which FET#A1 _(n), FET#A2_(n), FET#B1 _(n) and FET#B2 _(n) in the n^(th) column are arranged inthe same order of FET#A1 _(n), FET#A2 _(n), FET#B1 _(n) and FET#B2 _(n)as the (n−1)^(th) column, in that FET#A1 _(n), FET#A2 _(n), FET#B1 _(n)and FET#B2 _(n) in the n^(th) column adjacent to the (n−1)^(th) columnare arranged in order of FET#A1 _(n), FET#B1 _(n), FET#A2 _(n) andFET#B2 _(n) from the bottom (the same applies to . . . , the (n−4)^(th)column, the (n−2)^(th) column, the (n+2)^(th) column, the (n+4)^(th)column, . . . ).

Accordingly, in FIG. 10, in the adjacent (n−1)^(th) and n^(th) columns,FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1 _(n) of the n^(th)column face each other, and FET#B2 _(n−1) of the (n−1)^(th) column andFET#B2 _(n) of the n^(th) column face each other. Further, a parasiticcapacitance C#A1 _(n−1) is created between FET#A1 _(n−1) of the(n−1)^(th) column and FET#A1 _(n) of the n^(th) column that face eachother, and a parasitic capacitance C#B2 _(n−1) is created between FET#B2_(n−1) of the (n−1)^(th) column and FET#B2 _(n) of the n^(th) columnthat face each other. This point is common to FIG. 8.

Further, in FIG. 10, in the adjacent (n−1)^(th) and n^(th) columns,FET#A2 _(n−1) of the (n−1)^(th) column and FET#B1 _(n) of the n^(th)column face each other, and FET#B1 _(n−1) of the (n−1)^(th) column andFET#A2 _(n), of the n^(th) column face each other. Further, a parasiticcapacitance C#A2B1 _(n−1) is created between FET#A2 _(n−1) of the(n−1)^(th) column and FET#B1 _(n), of the n^(th) column that face eachother, and a parasitic capacitance C#B1A2 _(n−1) is created betweenFET#B1 _(n−1) of the (n−1)^(th) column and FET#A2 _(n) of the n^(th)column that face each other. This point differs from FIG. 8.

Here, in FIG. 10, in the (n−1)^(th) column and the n^(th) column, thefirst number num11 of the first division FET of the (n−1)^(th) columnand the first division FET of the n^(th) column that face each other isonly 1, i.e., a set of FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1_(n) of the n^(th) column.

Further, the second number num22 of the second division FET of the(n−1)^(th) column and the second division FET of the n^(th) column thatcorrespond to each other is only 1, i.e., a set of FET#B2 _(n−1) of the(n−1)^(th) column and FET#B2 _(n), of the n^(th) column.

Further, the third number num12 of the first division FET of the(n−1)^(th) column and the second division FET of the n^(th) column thatface each other is only 1, i.e., FET#A2 _(n−1) of the (n−1)^(th) columnand FET#B1 _(n), of the n^(th) column, and the fourth number num21 ofthe second division FET of the (n−1)^(th) column and the first divisionFET of the n^(th) column that face each other is only 1, i.e., FET#B1_(n−1) of the (n−1)^(th) column and FET#A2 _(n) of the n^(th) column.

Accordingly, the first number num11, the second number num22, the thirdnumber num12, and the fourth number num21 are all 1 and are equal.

Further, the parasitic capacitances C#A1 _(n−1), C#A2B1 _(n−1), C#B1A2_(n−1) and C#B2 _(n−1) have (substantially) the same value for the samereason as the parasitic capacitances C#A1 _(n−1), C#A2 _(n−1), C#B1_(n−1) and C#B2 _(n−1) described with reference to FIG. 8.

FIGS. 11 and 12 are circuit diagrams illustrating the differential pairof the comparator 61 _(n−1) of the (n−1)^(th) column and thedifferential pair of the comparator 61 _(n) of the n^(th) column, whichare adjacent to each other, between which parasitic capacitances arecreated as illustrated in FIG. 10.

Further, FIG. 11 is a circuit diagram illustrating FET#A_(n) andFET#B_(n) constituting the differential pair of the comparator 61 _(n)using FET#A1 _(n), FET#A2 _(n), FET#B1 _(n) and FET#B2 _(n) obtained bydividing FET#A_(n) and FET#B_(n), and FIG. 12 is a circuit diagramillustrating FET#A_(n) and FET#B_(n) constituting the differential pairof the comparator 61 _(n) as they are without dividing FET#A_(n) andFET#B_(n). Accordingly, FIGS. 11 and 12 are substantially the samecircuit diagrams.

As illustrated in FIGS. 11 and 12, the inversion input terminal IN1_(n−1) (connected to the gate of FET#A_(n−1) (FET#A1 _(n−1) and FET#A2_(n−1))) of the comparator 61 _(n−1) of the (n−1)^(th) column and theinversion input terminal IN1 _(n) (connected to the gate of FET#A_(n)(FET#A1 _(n) and FET#A2 _(n))) of the comparator 61 _(n) of the n^(th)column, which are adjacent to each other, are connected by a parasiticcapacitance C#A1 _(n−1). This point is common to the case of FIG. 9.

Further, the non-inversion input terminal IN2 _(n−1) (connected to thegate of FET#B_(n−1) (FET#B1 _(n−1) and FET#B2 _(n−1)) of the comparator61 _(n−1) of the (n−1)^(th) column and the non-inversion input terminalIN2 _(n) (connected to the gate of FET#B_(n) (FET#B1 _(n) and FET#B2_(n)) of the comparator 61 _(n) of the n^(th) column, which are adjacentto each other, are connected by a parasitic capacitance C#B2 _(n−1).This point is also common to the case of FIG. 9.

However, in FIGS. 11 and 12, the inversion input terminal IN1 _(n−1)(connected to the gate of FET#A_(n−1)) of the comparator 61 _(n−1) ofthe (n−1)^(th) column and the non-inversion input terminal IN2 _(n)(connected to the gate of FET#B_(n)) of the comparator 61 _(n) of then^(th) column, which are adjacent to each other, are connected by aparasitic capacitance C#A2B1 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) (connected to thegate of FET#B_(n−1)) of the comparator 61 _(n−1) of the (n−1)^(th)column and the inversion input terminal IN1 _(n) (connected to the gateof FET#A_(n)) of the comparator 61 _(n) of the n^(th) column areconnected by a parasitic capacitance C#B1A2 _(n−1).

Accordingly, for example, when voltage fluctuation caused by noise orthe like occurs in the inversion input terminal IN1 _(n−1) of thecomparator 61 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the inversion input terminal IN1 _(n) of the comparator 61_(n) of the n^(th) column adjacent to the (n−1)^(th) column via theparasitic capacitance C#A1 _(n−1). This is the same as the case of FIG.9.

However, in FIGS. 11 and 12, when the voltage fluctuation caused bynoise or the like occurs in the inversion input terminal IN l_(n−1) ofthe comparator 61 _(n−1) of the (n−1)^(th) column, the voltagefluctuation influences the non-inversion input terminal IN2 _(n) of thecomparator 61 _(n) of the n^(th) column adjacent to the (n−1)^(th)column via the parasitic capacitance C#A2B1 _(n−1).

As described with reference to FIG. 10, the parasitic capacitance C#A1_(n−1) and C#A2B1 _(n−1) have the same value, and therefore a degree ofthe voltage fluctuation occurring in the inversion input terminal INl_(n−1) of the comparator 61 _(n−1) of the (n−1)^(th) column influencingthe inversion input terminal IN1 _(n) of the comparator 61 _(n) of then^(th) column adjacent to the (n−1)^(th) column via the parasiticcapacitance C#A1 _(n−1) and a degree of the voltage fluctuationinfluencing the non-inversion input terminal IN2 of the comparator 61via the parasitic capacitance C#A2B1_, are the same.

In other words, when the voltage fluctuation occurs in the inversioninput terminal IN1_, of the comparator 61 _(n−1) of the (n−1)^(th)column, the voltage fluctuation occurring in the inversion inputterminal IN1 _(n) of the comparator 61 of the n^(th) column via theparasitic capacitance C#A1_, and the voltage fluctuation occurring inthe non-inversion input terminal IN2 _(n) of the comparator 61 _(n) ofthe n^(th) column via the parasitic capacitance C#A2B1 _(n−1), are ofthe same degree.

In the differential pair (FET#A_(n) and FET#B_(n)) to which theinversion input terminal IN1 _(n) and the non-inversion input terminalIN2 _(n) are connected in the comparator 61 of the n^(th) column, sincethe voltage fluctuations of the same degree occurring in both theinversion input terminal IN1 _(n) and the non-inversion input terminalIN2 _(n) are in-phase signals, the voltage fluctuations are canceled(canceled out) and do not influence the output (the voltage of outputterminal OUT_(n)) of the comparator 61 _(n) of the n^(th) column.

Further, for example, when the voltage fluctuation caused by noise orthe like occurs in the non-inversion input terminal IN2 _(n−1), of thecomparator 64 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column adjacent to the (n−1)^(th) column via theparasitic capacitance C#B2 _(n−1) and influences the inversion inputterminal IN1 _(n) of the comparator 61 _(n) of the n^(th) columnadjacent to the (n−1)^(th) column via the parasitic capacitance C#B1A2_(n−1), and voltage fluctuations of the same degree occur in theinversion input terminal IN1 _(n) and the non-inversion input terminalIN2 _(n) of the comparator 61 _(n) of the n^(th) column.

In the differential pair to which the inversion input terminal IN1 andthe non-inversion input terminal IN2 are connected in the comparator 61of the n^(th) column, since the voltage fluctuations of the same degreeoccurring in both the inversion input terminal IN1 _(n), and thenon-inversion input terminal IN2 _(n), are in-phase signals, the voltagefluctuations are canceled and do not influence the output of thecomparator 61 of the n^(th) column.

Further, the voltage fluctuation of the inversion input terminal IN1_(n), or the non-inversion input terminal IN2 _(n), of the comparator 61of the n^(th) column influences the inversion input terminal IN1 _(n+1)or the non-inversion input terminal IN2 _(n+1) of the comparator 61_(n+1) of the (n+1)^(th) column via the parasitic capacitance betweenthe n^(th) column and the (n+1)^(th) column, but in the differentialpair of the comparator 61 _(n+1) of the (n+1)^(th) column, the voltagefluctuations are canceled and do not influence the output of thecomparator 61 _(n+1) of the (n+1)^(th) column, as in the above-describedcase.

Accordingly, the voltage fluctuation of the inversion input terminal IN1_(n−1) or the non-inversion input terminal IN2 _(n−1) of the comparator61 _(n−1) of the (n−1)^(th) column does not influence the output of thecomparator 61 _(n) of the n^(th) column adjacent to the (n−1)^(th)column and also does not influence the output of the comparator 61_(n+1) of the (n+1)^(th) column via the parasitic capacitance betweenthe n^(th) column and the (n+1)^(th) column.

Since the voltage fluctuation of the inversion input terminal IN1 _(n−1)or the non-inversion input terminal IN2 _(n−1) of the comparator 61_(n−1) of the (n−1)^(th) column does not influence the output of thecomparator 61 _(n)′ of another column via the parasitic capacitance asdescribed above, it is possible to improve a crosstalk characteristic ofthe column parallel AD conversion unit 22.

In other words, it is possible to disperse the parasitic capacitancescreated between the adjacent (n−1)^(th) and n^(th) columns so that thecrosstalk is canceled in the differential pair of the comparator 61 _(n)by arranging FET#A1 _(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2_(n−1) of the (n−1)^(th) column and FET#A1 _(n), FET#A2 _(n), FET#B1_(n) and FET#B2 _(n) of the n^(th) column such that the arrangementpattern of FET#A1 _(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2 _(n−1)of any (n−1)^(th) column and an arrangement pattern of FET#A1 _(n),FET#A2 _(n), FET#B1 _(n), and FET#B2 _(n), of the n^(th) column(adjacent column) adjacent to the (n−1)^(th) column are different, andas a result, it is possible to improve the crosstalk characteristicwithout particularly causing a side effect.

FIG. 13 is a diagram illustrating a second example of the arrangement ofFET#A_(n) and FET#B_(n), improving a crosstalk characteristic.

Further, an illustration of (a capacitor indicating) the parasiticcapacitance between the n^(th) column and the (n+1)^(th) column isomitted in FIG. 13 (the same applies to the drawings below).

In FIG. 13, FET#A_(n) and FET#B_(n) are divided into FET#A1 _(n), andFET#A2 _(n), as two first division FETs and FET#B1 _(n), and FET#B2 n astwo second division FETs, respectively, as in the cases of FIGS. 8 and10.

In FIG. 13, FET#A1 _(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2_(n−1) are arranged in this order from a bottom in the (n−1)^(th) column(the same applies to . . . , the (n−5)^(th) column, the (n−3)^(th)column, the (n+1)^(th) column, the (n+3)^(th) column, . . . ).

Further, in FIG. 13, FET#A1 _(n), FET#A2 _(n), FET#B1 _(n), and FET#B2_(n) are arranged in order of FET#A1 _(n), FET#B2 _(n), FET#B1 _(n), andFET#A2 _(n), from the bottom in the n^(th) column adjacent to the(n−1)^(th) column (the same applies to . . . , the (n−4)^(th) column,the (n−2)^(th) column, the (n+2)^(th) column, the (n+4)^(th) column, . .. ).

Accordingly, even in FIG. 13, the first division FETs (FET#A1 _(n−1) andFET#A2 _(n−1)) and the second division FETs (FET#B1 _(n−1) and FET#B2_(n−1)) of the (n−1)^(th) column, and the first division FETs (FET#A1_(n), and FET#A2 _(n)) and the second division FETs (FET#B1 _(n), andFET#B2 _(n)) of the n^(th) column are arranged so that parasiticcapacitance coupling between FET#A_(n) as the first transistor of the(n−1)^(th) column and each of FET#A_(n) as the first transistor andFET#B_(n) as the second transistor of the n^(th) column (adjacentcolumn) adjacent to the (n−1)^(th) column is created and parasiticcapacitance coupling between FET#B_(n−1) as the second transistor of the(n−1)^(th) column and each of FET#A_(n) as the first transistor andFET#B_(n) of the second transistor of the n^(th) column adjacent to the(n−1)^(th) column is created, as in the case of FIG. 10.

Further, in FIG. 13, in (n−1)^(th) and n^(th) columns, FET#A1 _(n−1),FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2 _(n−1) of the (n−1)^(th) columnand FET#A1 _(n), FET#A2 _(n), FET#B1 _(n) and FET#B2 _(n) of the n^(th)column are arranged so that all of the first number num11 of the firstdivision FET of the (n−1)^(th) column and the first division FET of then^(th) column that face each other, the second number num22 of thesecond division FET of the (n−1)^(th) column and the second division FETof the n^(th) column that correspond to each other, the third numbernum12 of the first division FET of the (n−1)^(th) column and the seconddivision FET of the n^(th) column that face each other, and the fourthnumber num21 of the second division FET of the (n−1)^(th) column and thefirst division FET of the n^(th) column that face each other are equal,as in the case of FIG. 10.

In other words, in FIG. 13, in the adjacent (n−1)^(th) and n^(th)columns, FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1 _(n) of then^(th) column face each other, and FET#B1 _(n−1) of the (n−1)^(th)column and FET#B1 _(n) of the n^(th) column face each other. Further,the parasitic capacitance C#A1 _(n−1) is created between FET#A1 _(n−1)of the (n−1)^(th) column and FET#A1 _(n) of the n^(th) column that faceeach other, and the parasitic capacitance C#B1 _(n−1) is created betweenFET#B1 _(n−1) of the (n−1)^(th) column and FET#B1 _(n) of the n^(th)column that face each other.

Further, in FIG. 13, in the adjacent (n−1)^(th) and n^(th) columns,FET#A2 _(n−1) of the (n−1)^(th) column and FET#B2 _(n) of the n^(th)column face each other, and FET#B2 _(n−1) of the (n−1)^(th) column andFET#A2 _(n) of the n^(th) column face each other. Further, a parasiticcapacitance C#A2B2 _(n−1) is created between FET#A2 _(n−1) of the(n−1)^(th) column and FET#B2 _(n) of the n^(th) column that face eachother, and a parasitic capacitance C#B2A2 _(n−1) is created betweenFET#B2 _(n−1) of the (n−1)^(th) column and FET#A2 _(n) of the n^(th)column that face each other.

Accordingly, in FIG. 13, in the (n−1)^(th) column and the n^(th) column,the first number num11 of the first division FET of the (n−1)^(th)column and the first division FET of the n^(th) column that face eachother is only 1, i.e., a set of FET#A1 _(n−1) of the (n−1)^(th) columnand FET#A1 _(n) of the n^(th) column.

Further, the second number num22 of the second division FET of the(n−1)^(th) column and the second division FET of the n^(th) column thatcorrespond to each other is only 1, i.e., a set of FET#B1 _(n−1) of the(n−1)^(th) column and FET#B1 _(n) of the n^(th) column.

Further, the third number num12 of the first division FET of the(n−1)^(th) column and the second division FET of the n^(th) column thatface each other is only 1, i.e., a set of FET#A2 _(n−1) of the(n−1)^(th) column and FET#B2 _(n), of the n^(th) column, and the fourthnumber num21 of the second division FET of the (n−1)^(th) column and thefirst division FET of the n^(th) column that face each other is only 1,i.e., a set of FET#B2 _(n−1) of the (n−1)^(th) column and FET#A2 _(n) ofthe n^(th) column.

Accordingly, the first number num11, the second number num22, the thirdnumber num12, and the fourth number num21 are all 1 and are equal.

Further, the parasitic capacitances C#A1 _(n−1), C#A2B2 _(n−1), C#B2A2_(n−1) and C#B1 _(n−1) have (substantially) the same value for the samereason as illustrated in FIG. 8 or 10.

FIG. 14 is a circuit diagram illustrating the differential pair of thecomparator 61 _(n−1) of the (n−1)^(th) column and the differential pairof the comparator 61 _(n) of the n^(th) column that are adjacent eachother, in which parasitic capacitances are created as illustrated inFIG. 13.

Further, FIG. 14 is a circuit diagram illustrating FET#A_(n) andFET#B_(n) constituting the differential pair of the comparator 61 asthey are without dividing FET#A_(n) and FET#B_(n), as in FIG. 12.

As illustrated in FIG. 14, the inversion input terminal IN1 _(n−1)(connected to the gate of FET#A_(n−1)) of the comparator 61 _(n−1) ofthe (n−1)^(th) column and the inversion input terminal IN1 _(n)(connected to the gate of FET#A_(n)) of the comparator 61 _(n) of then^(th) column which are adjacent are connected by the parasiticcapacitance C#A1 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) (connected to thegate of FET#B_(n−1)) of the comparator 61 _(n−1) of the (n−1)^(th)column and the non-inversion input terminal IN2 _(n) (connected to thegate of FET#B_(n)) of the comparator 61 _(n) of the n^(th) column whichare adjacent are connected by the parasitic capacitance C#B1 _(n−1).

Further, the inversion input terminal IN1 _(n−1) (connected to the gateof FET#A_(n−1)) of the comparator 61 _(n−1) of the (n−1)^(th) column andthe non-inversion input terminal IN2 _(n) (connected to the gate ofFET#B_(n)) of the comparator 61 _(n) of the n^(th) column which areadjacent are connected by the parasitic capacitance C#A2B2 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) (connected to thegate of FET#B_(n−1)) of the comparator 61 _(n−1) of the (n−1)^(th)column and the inversion input terminal IN1 _(n) (connected to the gateof FET#A_(n)) of the comparator 61 _(n) of the n^(th) column which areadjacent are connected by the parasitic capacitance C#B2A2 _(n−1).

Accordingly, for example, when the voltage fluctuation caused by noiseor the like occurs in the inversion input terminal IN1 _(n−1) of thecomparator 61 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the inversion input terminal IN1 _(n) of the comparator 61_(n) of the n^(th) column adjacent to the (n−1)^(th) column via theparasitic capacitance C#A1 _(n−1), and influences the non-inversioninput terminal IN2 _(n) of the comparator 61 _(n) via the parasiticcapacitance C#A2B2 _(n−1), and voltage fluctuations of the same degreeoccur in the inversion input terminal IN1 _(n) and the non-inversioninput terminal IN2 _(n) of the comparator 61 _(n) of the n^(th) column.

In the differential pair to which the inversion input terminal IN1 _(n)and the non-inversion input terminal IN2 _(n) are connected in thecomparator 61 _(n) of the n^(th) column, since the voltage fluctuationsof the same degree occurring in both the inversion input terminal IN1_(n) and the non-inversion input terminal IN2 _(n) are in-phase signals,the voltage fluctuations are canceled and do not influence the output ofthe comparator 61 _(n) of the n^(th) column.

Further, for example, when the voltage fluctuation caused by noise orthe like occurs in the non-inversion input terminal IN2 _(n−1) of thecomparator 64 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column adjacent to the (n−1)^(th) column via theparasitic capacitance C#B1 _(n−1) and influences the inversion inputterminal IN1 _(n) of the comparator 61 via the parasitic capacitanceC#B2A2 _(n−1), and voltage fluctuations of the same degree occur in theinversion input terminal IN1 _(n), and the non-inversion input terminalIN2 _(n) of the comparator 61 _(n) of the n^(th) column.

In the differential pair to which the inversion input terminal IN1 _(n)and the non-inversion input terminal IN2 _(n) are connected in thecomparator 61 _(n) of the n^(th) column, since the voltage fluctuationsof the same degree occurring in both the inversion input terminal IN1_(n) and the non-inversion input terminal IN2 _(n), are in-phasesignals, the voltage fluctuations are canceled and do not influence theoutput of the comparator 61 _(n) of the n^(th) column.

As described above, the voltage fluctuation of the inversion inputterminal IN1 _(n−1) or the non-inversion input terminal IN2 _(n−1) ofthe comparator 61 _(n−1) of the (n−1)^(th) column does not influence theoutput of the comparator 61 _(n) of the adjacent n^(th) column (and thecomparator 61 _(n)′ of the other column) via the parasitic capacitances.Accordingly, in the adjacent (n−1)^(th) and n^(th) columns, when FET#A1_(n−1), FET#A2 _(n−1), FET#B1 _(n−1) and FET#B2 _(n−1) of the (n−1)^(th)column and FET#A1 _(n), FET#A2 _(n), FET#B1 _(n) and FET#B2 _(n) of then^(th) column are arranged in the different arrangement patterns asillustrated in FIG. 13, it is possible to improve a crosstalkcharacteristic of the column parallel AD conversion unit 22, as in thecase of FIG. 10.

FIG. 15 is a diagram illustrating a third example of the arrangement ofFET#A_(n) and FET#B_(n) improving a crosstalk characteristic.

In FIG. 15, FET#A_(n) and FET#B_(n) are divided into FET#A1 _(n), FET#A2_(n), FET#A3 _(n) and FET#A4 _(n) as four first division FETs and intoFET#B1 _(n), FET#B2 _(n), FET#B3 _(n) and FET#B4 _(n) as four seconddivision FETs, which have the same size.

Further, in FIG. 15, in the (n−1)^(th) column, FET#A1 _(n−1) to FET#A4_(n−1) and FET#B1 _(n−1) to FET#B4 _(n−1) are arranged in order ofFET#A1 _(n−1), FET#A2 _(n−1), FET#A3 _(n−1), FET#A4 _(n−1), FET#B1_(n−1), FET#B2 _(n−1), FET#B3 _(n−1) and FET#B4 _(n−1) from a bottom(the same applies to . . . , the (n−5)^(th) column, the (n−3)^(th)column, the (n+1)^(th) column, the (n+3)^(th) column, . . . ).

Further, in FIG. 15, in the n^(th) column adjacent to the (n−1)^(th)column, FET#A1 _(n) to FET#A4 _(n) and FET#B1 _(n) to FET#B4 _(n) arearranged in order of FET#A1 _(n), FET#A2 _(n), FET#B1 _(n), FET#B2 _(n),FET#A3 _(n), FET#A4 _(n), FET#B3 _(n) and FET#B4 _(n) from the bottom(the same applies to . . . , the (n−4)^(th) column, the (n−2)^(th)column, the (n+2)^(th) column, the (n+4)^(th) column, . . . ).

Accordingly, even in FIG. 15, an arrangement pattern of FET#A1 _(n−1) toFET#A4 _(n−1) and FET#B1 _(n−1) to FET#B4 _(n−1) of any (n−1)^(th)column (an arrangement order of FET#A1 _(n−1) to FET#A4 _(n−1) andFET#B1 _(n−1) to FET#B4 _(n−1) arranged side by side in the columndirection) and an arrangement pattern of FET#A1 _(n) to FET#A4 _(n) andFET#B1 _(n) to FET#B4 _(n) of the n^(th) column (adjacent column)adjacent to the (n−1)^(th) column are different from each other, as inFIGS. 10 and 13.

In FIG. 15, FET#A1 _(n−1) to FET#A4 _(n−1) as the first division FETsand FET#B1 _(n−1) to FET#B4 _(n−1) as the second division FETs in the(n−1)^(th) column, and FET#A1 _(n) to FET#A4 _(n) as the first divisionFETs and FET#B1 _(n) to FET#B4 _(n) as the second division FETs in then^(th) column are arranged so that parasitic capacitance couplingbetween FET#A_(n−1) as the first transistor in the (n−1)^(th) column andeach of FET#A_(n) as the first transistor and FET#B_(n) as the secondtransistor in the n^(th) column adjacent to the (n−1)^(th) column iscreated and parasitic capacitance coupling between FET#B_(n−1) as thesecond transistor in the (n−1)^(th) column and each of FET#A_(n) as thefirst transistor and FET#B_(n) as the second transistor in the n^(th)column adjacent to the (n−1)^(th) column is created, as in the case ofFIG. 10 or 13.

Further, in FIG. 15, in the (n−1)^(th) column and the n^(th) column,FET#A1 _(n1−1) to FET#A4 _(n−1) and FET#B1 _(n−1) to FET#B4 _(n−1) ofthe (n−1)^(th) column and FET#A1 _(n) to FET#A4 _(n−1) and FET#B1 _(n)to FET#B4 _(n) of the n^(th) column are arranged so that all of thefirst number num11 of the first division FET of the (n−1)^(th) columnand the first division FET of the n^(th) column that face each other,the second number num22 of the second division FET of the (n−1)^(th)column and the second division FET of the n^(th) column that face eachother, the third number num12 of the first division FET of the(n−1)^(th) column and the second division FET of the n^(th) column thatface each other, and the fourth number num21 of the second division FETof the (n−1)^(th) column and the first division FET of the n^(th) columnthat face each other are equal, as in the case of FIG. 10 or 13.

In other words, in FIG. 15, in the adjacent (n−1)^(th) and n^(th)columns, FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1 _(n), of then^(th) column face each other, and FET#A2 _(n−1) of the (n−1)^(th)column and FET#A2 _(n), of the n^(th) column face each other. Further,the parasitic capacitance C#A1 _(n−1) is created between FET#A1 _(n−1)of the (n−1)^(th) column and FET#A1 _(n), of the n^(th) column that faceeach other, and a parasitic capacitance C#A2 _(n−1) is created betweenFET#A2 _(n−1) of the (n−1)^(th) column and FET#A2 _(n), of the n^(th)column that face each other.

Further, in FIG. 15, in the adjacent (n−1)^(th) and n^(th) columns,FET#A3 _(n−1) of the (n−1)^(th) column and FET#B1 _(n) of the n^(th)column face each other, and FET#A4 _(n−1) of the (n−1)^(th) column andFET#B2 _(n) of the n^(th) column face each other. Further, a parasiticcapacitance C#A3B1 _(n−1) is created between FET#A3 _(n−1) of the(n−1)^(th) column and FET#B1 _(n) of the n^(th) column that face eachother, and a parasitic capacitance C#A4B2 _(n−1) is created betweenFET#A4 _(n−1) of the (n−1)^(th) column and FET#B2 _(n) of the n^(th)column that face each other.

Further, in FIG. 15, in the adjacent (n−1)^(th) and n^(th) columns,FET#B1 _(n−1) of the (n−1)^(th) column and FET#A3 _(n) of the n^(th)column face each other, and FET#B2 _(n−1) of the (n−1)^(th) column andFET#A4 _(n) of the n^(th) column face each other. Further, a parasiticcapacitance C#B1A3 _(n−1) is created between FET#B1 _(n−1) of the(n−1)^(th) column and FET#A3 _(n) of the n^(th) column, and a parasiticcapacitance C#B2A4 _(n−1) is created between FET#B2 _(n−1) of the(n−1)^(th) column and FET#A4 _(n) of the n^(th) column that face eachother.

Further, in FIG. 15, in the adjacent (n−1)^(th) and n^(th) columns,FET#B3 _(n−1) of the (n−1)^(th) column and FET#B3 _(n) of the n^(th)column face each other, and FET#B4 _(n−1) of the (n−1)^(th) column andFET#B4 _(n) of the n^(th) column face each other. Further, a parasiticcapacitance C#B3 _(n−1) is created between FET#B3 _(n−1) of the(n−1)^(th) column and FET#B3 _(n) of the n^(th) column that face eachother, and a parasitic capacitance C#B4 _(n−1) is created between FET#B4_(n−1) of the (n−1)^(th) column and FET#B4 _(n) of the n^(th) columnthat face each other.

Accordingly, in FIG. 15, in the (n−1)^(th) column and the n^(th) column,the first number num11 of the first division FETs of the (n−1)^(th)column and the first division FETs of the n^(th) column that face eachother is 2: a set of FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1_(n) of the n^(th) column and a set of FET#A2 _(n−1) of the (n−1)^(th)column and FET#A2 _(n) of the n^(th) column.

Further, the second number num22 of the second division FETs of the(n−1)^(th) column and the second division FETs of the n^(th) column thatcorrespond to each other is 2: a set of FET#B3 _(n−1) of the (n−1)^(th)column and FET#B3 _(n) of the n^(th) column and a set of FET#B4 _(n−1)of the (n−1)^(th) column and FET#B4 _(n) of the n^(th) column.

Further, the third number num12 of the first division FET of the(n−1)^(th) column and the second division FET of the n^(th) column thatface each other is 2: a set of FET#A3 _(n−1) of the (n−1)^(th) columnand FET#B1 _(n) of the n^(th) column and a set of FET#A4 _(n−1) of the(n−1)^(th) column and FET#B2 _(n) of the n^(th) column, and the fourthnumber num21 of the second division FET of the (n−1)^(th) column and thefirst division FET of the n^(th) column that face each other is 2: a setof FET#B1 _(n−1) of the (n−1)^(th) column and FET#A3 _(n) of the n^(th)column and a set of FET#B2 _(n−1) of the (n−1)^(th) column and FET#A4_(n) of the n^(th) column.

Accordingly, the first number num11, the second number num22, the thirdnumber num12, and the fourth number num21 are all equal and are 2.

Further, in the parasitic capacitances C#A1 _(n−1), C#A2 _(n−1), C#A3131_(n−1), C#A4B2 _(n−1), C#B1A3 _(n−1), C#B2A4 _(n−1), C#B3 _(n−1) andC#B4 _(n−1), have (substantially) the same value for the same reason asillustrated in FIG. 8 or 10.

FIG. 16 is a circuit diagram illustrating the differential pair of thecomparator 61 _(n−1) of the (n−1)^(th) column and the differential pairof the comparator 61 _(n) of the n^(th) column, which are adjacent, andin which parasitic capacitances are created as illustrated in FIG. 15.

Further, FIG. 16 is a circuit diagram illustrating FET#A_(n) andFET#B_(n) constituting the differential pair of the comparator 61 _(n)as they are without dividing FET#A_(n) and FET#B_(n), as in FIG. 12.

As illustrated in FIG. 16, the inversion input terminal IN1 _(n−1) ofthe comparator 61 _(n−1) of the (n−1)^(th) column and the inversioninput terminal IN1 _(n) of the comparator 61 _(n) of the n^(th) columnthat are adjacent to each other are coupled by each of parasiticcapacitances C#A1 _(n−1) and C#A2 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) of the comparator61 _(n−1) of the (n−1)^(th) column and the non-inversion input terminalIN2 _(n) of the comparator 61 _(n) of the n^(th) column that areadjacent to each other are coupled by each of parasitic capacitancesC#B3 _(n−1) and C#B4 _(n−1).

Furthermore, the inversion input terminal IN1 _(n−1) of the comparator61 _(n−1) of the (n−1)^(th) column and the non-inversion input terminalIN2 _(n) of the comparator 61 _(n) of the n^(th) column that areadjacent to each other are coupled by each of parasitic capacitancesC#A3B1 _(n−1) and C#A4B2 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) of the comparator61 _(n−1) of the (n−1)^(th) column and the inversion input terminal IN1_(n) of the comparator 61 _(n) of the n^(th) column that are adjacent toeach other are coupled by each of parasitic capacitances C#B2A4 _(n−1)and C#B1A3 _(n−1).

Accordingly, for example, when voltage fluctuation caused by noise orthe like occurs in the inversion input terminal IN1 _(n−1) of thecomparator 61 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the inversion input terminal IN1 _(n) of the comparator 61_(n) of the n^(th) column adjacent to the (n−1)^(th) column via each ofthe parasitic capacitances C#A1 _(n−1) and C#A2 _(n−1) and influencesthe non-inversion input terminal IN2 _(n) of the comparator 61 _(n) ofthe n^(th) column adjacent to the (n−1)^(th) column via each of theparasitic capacitances C#A3B1 _(n−1) and C#A4B2 _(n−1), and voltagefluctuations of the same degree occur in the inversion input terminalIN1 _(n) and the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column.

Further, for example, when voltage fluctuation caused by noise or thelike occurs in the non-inversion input terminal IN2 _(n−1) of thecomparator 61 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the non-inversion input terminal IN2 of the comparator 61_(n) of the n^(th) column adjacent to the (n−1)^(th) column via each ofthe parasitic capacitances C#B3 _(n−1) and C#B4 _(n−1) and influencesthe inversion input terminal IN1 _(n), of the comparator 61 _(n) of then^(th) column adjacent to the (n−1)^(th) column via each of theparasitic capacitances C#B2A4 _(n−1) and C#B1A3 _(n−1), and voltagefluctuations of the same degree occur in the inversion input terminalIN1 _(n) and the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column.

In the comparator 61 _(n) of the n^(th) column, since the voltagefluctuations of the same degree occurring in both the inversion inputterminal IN1 _(n) and the non-inversion input terminal IN2 _(n) in thedifferential pair to which the inversion input terminal IN1 _(n) and thenon-inversion input terminal IN2 _(n) are connected are in-phasesignals, the voltage fluctuations are canceled and do not influence theoutput of the comparator 61 _(n) of the n^(th) column.

As described above, the voltage fluctuation of the inversion inputterminal IN1 _(n−1) or the non-inversion input terminal IN2 _(n−1) ofthe comparator 64 _(n−1) of the (n−1)^(th) column does not influence theoutput of the comparator 61 _(n) of the adjacent n^(th) column (and thecomparator 61 _(n)′ of the other column) via the parasitic capacitances.Accordingly, in the adjacent (n−1)^(th) and n^(th) columns, when FET#A1_(n−1) to FET#A4 _(n−1) and FET#B1 _(n−1) to FET#B4 _(n−1) of the(n−1)^(th) column and FET#A1 _(n) to FET#A4 _(n) and FET#B1 _(n) toFET#B4 _(n) of the n^(th) column are arranged in the differentarrangement patterns illustrated in FIG. 15, it is possible to improve acrosstalk characteristic of the column parallel AD conversion unit 22,as in the case of FIG. 10.

Here, in the adjacent (n−1)^(th) and n^(th) columns, the first divisionFET and the second division FET of the (n−1)^(th) column and the firstdivision FET and the second division FET of the n^(th) column arearranged so that all of the first number num11 of the first division FETof the (n−1)^(th) column and the first division FET of the n^(th) columnthat face each other, the second number num22 of the second division FETof the (n−1)^(th) column and the second division FET of the n^(th)column that correspond to each other, the third number num12 of thefirst division FET of the (n−1)^(th) column and the second division FETof the n^(th) column that face each other, and the fourth number num21of the second division FET of the (n−1)^(th) column and the firstdivision FET of the n^(th) column that face each other are equal, asillustrated in FIGS. 10 to 16, and accordingly, for example, even whenvoltage fluctuation occurs in the inversion input terminal IN1 _(n−1)and the non-inversion input terminal IN2 _(n−1) of the comparator 61_(n−1) of the (n−1)^(th) column, this voltage fluctuation causes voltagefluctuations of the same degree in both the inversion input terminal IN1_(n) and the non-inversion input terminal IN2 _(n) of the comparator 61in the n^(th) column adjacent to the (n−1)^(th) column via each of theplurality of the same parasitic capacitances.

Further, in the differential pair of the comparator 61 of the n^(th)column, the voltage fluctuations of the same degree occurring in boththe inversion input terminal IN1 _(n) and the non-inversion inputterminal IN2 _(n) are canceled, and as a result, the voltagefluctuations occurring in the inversion input terminal IN1 _(n−1) andthe non-inversion input terminal IN2 _(n−1) of the comparator 61 _(n−1)of the (n−1)^(th) column do not influence the output of the comparator61 _(n) of the n^(th) column, thereby improving a crosstalkcharacteristic of the column parallel AD conversion unit 22.

As described above, it is necessary for the first number num11 to thefourth number num4 for the first division FETs and the second divisionFETs arranged in the adjacent (n−1)^(th) and n^(th) columns to match(equal) in order for the voltage fluctuations occurring in the inversioninput terminal IN1 _(n−1) and the non-inversion input terminal IN2_(n−1), of the comparator 61 _(n−1) of the (n−1)^(th) column to becanceled as the voltage fluctuations of the same degree occurring inboth the inversion input terminal IN1 _(n) and the non-inversion inputterminal IN2 _(n) of the comparator 61 _(n) in the differential pair ofthe comparator 61 _(n) of the n^(th) column adjacent to the (n−1)^(th)column.

Further, it is necessary to divide each of FET#A_(n) and FET#B_(n),constituting the differential pair in (the same) even numbers to causethe first number num11 to the fourth number num4 to match.

However, even when each of FET#A_(n) and FET#B_(n) constituting thedifferential pair is divided in an odd number, it is possible to improvea crosstalk characteristic of the column parallel AD conversion unit 22by arranging the first division FETs into which FET#A_(n−1) has beendivided and the second division FETs into which FET#B_(n−1) has beendivided, which constitute the differential pair in the (n−1)^(th)column, and the first division FETs into which FET#A_(n) has beendivided and the second division FETs into which FET#B_(n) has beendivided, which constitute the differential pair in the n^(th) columnadjacent to the (n−1)^(th) column, in the different arrangementpatterns, so that the first number num11 to the fourth number num4 matchif possible, in comparison with the case in which the arrangement in thesame arrangement patterns as illustrated in FIG. 8 is performed.

FIG. 17 is a diagram illustrating a fourth example of the arrangement ofFET#A_(n) and FET#B_(n) improving the crosstalk characteristic.

In FIG. 17, FET#A_(n) and FET#B_(n) are divided into FET#A1 _(n), FET#A2_(n) and FET#A3 _(n) as an odd number of, i.e., three, first divisionFETs having the same size and FET#B1 _(n), FET#B2 _(n) and FET#B3 _(n)as an odd number of, i.e., three, second division FETs having the samesize.

Further, in FIG. 17, FET#A1 _(n−1) to FET#A3 _(n−1) and FET#B1 _(n−1) toFET#B3 _(n−1) are arranged in order of FET#A1 _(n−1), FET#A2 _(n−1),FET#A3 _(n−1), FET#B1 _(n−1), FET#B2 _(n−1) and FET#B3 _(n−1) from abottom in the (n−1)^(th) column (the same applies to . . . , the(n−5)^(th) column, the (n−3)^(th) column, the (n+1)^(th) column, the(n+3)^(th) column, . . . ).

Further, in FIG. 17, FET#A1 _(n) to FET#A3 _(n) and FET#B1 _(n) toFET#B3 _(n) are arranged in order of FET#A1 _(n), FET#A2 _(n), FET#B1_(n), FET#A3 _(n), FET#B2 _(n) and FET#B3 _(n) from a bottom in then^(th) column adjacent to the (n−1)^(th) column (the same applies to . .. , the (n−4)^(th) column, the (n−2)^(th) column, the (n+2)^(th) column,the (n+4)^(th) column, . . . ).

Accordingly, in FIG. 17, an arrangement pattern of FET#A1 _(n−1) toFET#A3 _(n−1) and FET#B1 _(n−1) to FET#B3 _(n−1) of any (n−1)^(th)column is different from the arrangement pattern of FET#A1 _(n) toFET#A3 _(n) and FET#B1 _(n) to FET#B3 _(n) of the n^(th) column(adjacent column) adjacent to the (n−1)^(th) column, as in FIG. 10, 13or 15.

Further, in FIG. 17, FET#A1 _(n−1) to FET#A3 _(n−1) as first divisionFETs and FET#B1 _(n−1) to FET#B3 _(n−1) as the second division FETs ofthe (n−1)^(th) column and FET#A1 _(n), to FET#A3 _(n) as the firstdivision FETs and FET#B1 _(n) to FET#B3 _(n) as the second division FETsof the n^(th) column are arranged so that parasitic capacitance couplingbetween FET#A_(n−1) as the first transistor of the (n−1)^(th) column andeach of FET#A_(n) as the first transistor and FET#B_(n) as the secondtransistor of the n^(th) column adjacent to the (n−1)^(th) column iscreated and parasitic capacitance coupling between FET#B_(n−1) as thesecond transistor of the (n−1)^(th) column and each of FET#A_(n) as thefirst transistor and FET#B_(n) as the second transistor of the n^(th)column (adjacent column) adjacent to the (n−1)^(th) column is created,as in the case of FIG. 10, 13 or 15.

However, in FIG. 17, since each of FET#A_(n) and FET#B_(n) is divided inan odd number, i.e., three, the first number num11 of the first divisionFET of the (n−1)^(th) column and the first division FET of the n^(th)column that face each other, the second number num22 of the seconddivision FET in the (n−1)^(th) column and the second division FET in then^(th) column that face each other, the third number num12 of the firstdivision FET in the (n−1)^(th) column and the second division FET in then^(th) column that face each other, and the fourth number num21 of thesecond division FET in the (n−1)^(th) column and the first division FETin the n^(th) column that face each other do not completely match in the(n−1)^(th) column and the n^(th) column. Accordingly, in FIG. 17, FET#A1_(n−1) to FET#A3 _(n−1) and FET#B1 _(n−1) to FET#B3 _(n−1) of the(n−1)^(th) column and FET#A1 _(n) to FET#A3 _(n) and FET#B1 _(n) toFET#B3 _(n) of the n^(th) column are arranged so that the first numbernum11, the second number num22, the third number num12 and the fourthnumber num21 match if possible.

In other words, in FIG. 17, in the adjacent (n−1)^(th) and n^(th)columns, FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1 _(n) of then^(th) column face each other, and FET#A2 _(n−1) of the (n−1)^(th)column and FET#A2 _(n) of the n^(th) column face each other. Further, aparasitic capacitance C#A1 _(n−1) is created between FET#A1 _(n−1) ofthe (n−1)^(th) column and FET#A1 _(n) of the n^(th) column that faceeach other, and a parasitic capacitance C#A2 _(n−1) is created betweenFET#A2 _(n−1) of the (n−1)^(th) column and FET#A2 _(n) of the n^(th)column that face each other.

Further, in FIG. 17, in the adjacent (n−1)^(th) and n^(th) columns,FET#A3 _(n−1) of the (n−1)^(th) column and FET#B1 _(n) of the n^(th)column face each other, and FET#B1 _(n−1) of the (n−1)^(th) column andFET#A3 _(n) of the n^(th) column face each other. Further, a parasiticcapacitance C#A3B1 _(n−1) is created between FET#A3 _(n−1) of the(n−1)^(th) column and FET#B1 _(n) of the n^(th) column that face eachother, and a parasitic capacitance C#B1A3 _(n−1) is created betweenFET#B1 _(n−1) of the (n−1)^(th) column and FET#A3 _(n) of the n^(th)column.

Further, in FIG. 17, in the adjacent (n−1)^(th) and n^(th) columns,FET#B2 _(n−1) of the (n−1)^(th) column and FET#B2 _(n) of the n^(th)column face each other, and FET#B3 _(n−1) of the (n−1)^(th) column andFET#B3 _(n) of the n^(th) column face each other. Further, a parasiticcapacitance C#B2 _(n−1) is created between FET#B2 _(n−1) of the(n−1)^(th) column and FET#B2 _(n) of the n^(th) column that face eachother, and a parasitic capacitance C#B3 _(n−1) is created between FET#B3_(n−1) of the (n−1)^(th) column and FET#B3 _(n) of the n^(th) columnthat face each other.

Accordingly, in FIG. 17, in the (n−1)^(th) column and the n^(th) column,the first number num11 of the first division FETs of the (n−1)^(th)column and the first division FETs of the n^(th) column that face eachother is 2: a set of FET#A1 _(n−1) of the (n−1)^(th) column and FET#A1_(n) of the n^(th) column and a set of FET#A2 _(n−1) of the (n−1)^(th)column and FET#A2 _(n) of the n^(th) column.

Further, the second number num22 of the second division FETs of the(n−1)^(th) column and the second division FETs of the n^(th) column thatcorrespond to each other is 2: a set of FET#B2 _(n−1) of the (n−1)^(th)column and FET#B2 _(n) of the n^(th) column and a set of FET#B3 _(n−1)of the (n−1)^(th) column and FET#B3 _(n) of the n^(th) column.

Further, the third number num12 of the first division FET of the(n−1)^(th) column and the second division FET of the n^(th) column thatface each other is 1, i.e., a set of FET#A3 _(n−1) of the (n−1)^(th)column and FET#B1 _(n) of the n^(th) column, and the fourth number num21of the second division FET of the (n−1)^(th) column and the firstdivision FET of the n^(th) column that face each other is 1, i.e., a setof FET#B1 _(n−1) of the (n−1)^(th) column and FET#A3 _(n) of the n^(th)column.

Accordingly, the first number num11, the second number num22, the thirdnumber num12 and the fourth number num21 have a difference of at most 1,and have a matching value, if possible.

Further, the parasitic capacitances C#A1 _(n−1), C#A2 _(n−1), C#A3B1_(n−1), C#B1A3 _(n−1), C#B2 _(n−1) and C#B3 _(n−1) have (substantially)the same values for the same reason as described with reference to FIG.8 or 10.

FIG. 18 is a circuit diagram illustrating the differential pair of thecomparator 61 _(n−1) of the (n−1)^(th) column and the differential pairof the comparator 61 _(n) of the n^(th) column that are adjacent to eachother, in which parasitic capacitances are created as illustrated inFIG. 17.

Further, FIG. 18 is a circuit diagram illustrating FET#A_(n) andFET#B_(n) constituting the differential pair of the comparator 61 _(n)as they are without dividing FET#A_(n) and FET#B_(n), as in FIG. 12 or16.

As illustrated in FIG. 18, the inversion input terminal IN1 _(n−1) ofthe comparator 61 _(n−1) of the (n−1)^(th) column and the inversioninput terminal IN1 _(n) of the comparator 61 _(n) of the n^(th) columnthat are adjacent to each other are coupled by respective parasiticcapacitances C#A1 _(n−1) and C#A2 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) of the comparator61 _(n−1) of the (n−1)^(th) column and the non-inversion input terminalIN2 _(n) of the comparator 61 _(n) of the n^(th) column that areadjacent to each other are coupled by respective parasitic capacitancesC#B2 _(n−1) and C#B3 _(n−1).

Further, the inversion input terminal IN1 _(n−1) of the comparator 61_(n−1) of the (n−1)^(th) column and the non-inversion input terminal IN2_(n) of the comparator 61 _(n) of the n^(th) column that are adjacent toeach other are coupled by a parasitic capacitance C#A3B1 _(n−1).

Further, the non-inversion input terminal IN2 _(n−1) of the comparator61 _(n−1) of the (n−1)^(th) column and the inversion input terminal IN1_(n) of the comparator 61 _(n) of the n^(th) column that are adjacent toeach other are coupled by a parasitic capacitance C#B1A3 _(n−1).

Accordingly, for example, when voltage fluctuation caused by noise orthe like occurs in the inversion input terminal IN1 _(n−1) of thecomparator 61 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the inversion input terminal IN1 _(n) of the comparator 61_(n) of the n^(th) column adjacent to the (n−1)^(th) column via therespective two parasitic capacitances C#A1 _(n−1) and C#A2 _(n−1) andinfluences the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column adjacent to the (n−1)^(th) column via theone parasitic capacitance C#A3B1 _(n−1), and voltage fluctuation occursin the inversion input terminal IN1 _(n) and the non-inversion inputterminal IN2 _(n) of the comparator 61 _(n) of the n^(th) column.

A degree of the occurring voltage fluctuation is different between theinversion input terminal IN1 _(n) influenced by the voltage fluctuationof the inversion input terminal IN1_(n−1) via each of the two parasiticcapacitances C#A1 _(n−1) and C#A2 _(n−1) and the non-inversion inputterminal IN2 _(n) influenced by the voltage fluctuation of the inversioninput terminal IN1 _(n−1) via the one parasitic capacitance C#A3B1_(n−1), but nevertheless, in the differential pair of the comparator 61_(n) of the n^(th) column, a part (in-phase component) of the voltagefluctuation occurring in one of the inversion input terminal IN1 _(n)and the non-inversion input terminal IN2 _(n) is canceled by the voltagefluctuation occurring in the other.

Further, for example, when the voltage fluctuation caused by noise orthe like occurs in the non-inversion input terminal IN2 _(n−1) of thecomparator 61 _(n−1) of the (n−1)^(th) column, the voltage fluctuationinfluences the non-inversion input terminal IN2 _(n) of the comparator61 _(n) of the n^(th) column adjacent to the (n−1)^(th) column via thetwo parasitic capacitances C#B2 _(n−1) and C#B3 _(n−1) and influencesthe inversion input terminal IN1 _(n) of the comparator 61 _(n) of then^(th) column adjacent to the (n−1)^(th) column via the one parasiticcapacitance C#B1A3 _(n−1), and voltage fluctuation occurs in theinversion input terminal IN1 _(n) and the non-inversion input terminalIN2 _(n) of the comparator 61 _(n) of the n^(th) column.

A degree of the occurring voltage fluctuation is different between thenon-inversion input terminal IN2 _(n) influenced by the voltagefluctuation of the non-inversion input terminal IN2 _(n−1) via each ofthe two parasitic capacitances C#B2 _(n−1) and C#B3 _(n−1) and theinversion input terminal IN1 _(n) influenced by the voltage fluctuationof the non-inversion input terminal IN2 _(n−1) via the one parasiticcapacitance C#B1A3 _(n−1), but nevertheless, in the differential pair ofthe comparator 61 _(n) of the n^(th) column, a part of the voltagefluctuation occurring in one of the inversion input terminal IN1 _(n),and the non-inversion input terminal IN2 _(n) is canceled by the voltagefluctuation occurring in the other.

As described above, when each of FET#A_(n) and FET#B_(n) constitutingthe differential pair is divided in an odd number, degrees of thevoltage fluctuations in the inversion input terminal IN1 _(n), and thenon-inversion input terminal IN2 _(n) of the differential pair of then^(th) column adjacent to the (n−1)^(th) column caused by the voltagefluctuation of the inversion input terminal IN1 _(n−1) and thenon-inversion input terminal IN2 _(n−1) of the differential pair of the(n−1)^(th) column via the parasitic capacitances is different, butnevertheless, in the differential pair of the comparator 61 _(n) of then^(th) column, a part of the voltage fluctuation occurring in one of theinversion input terminal IN1 _(n) and the non-inversion input terminalIN2 _(n) is canceled by the voltage fluctuation occurring in the other.

Accordingly, even when each of FET#A_(n) and FET#B_(n) constituting thedifferential pair is divided in odd numbers, it is possible to improve acrosstalk characteristic of the column parallel AD conversion unit 22 byarranging the first division FETs into which FET#A_(n−1) has beendivided and the second division FETs into which FET#B_(n−1) has beendivided, which constitute the differential pair in the (n−1)^(th)column, and the first division FETs into which FET#A_(n) has beendivided and the second division FETs into which FET#B_(n) has beendivided, which constitute the differential pair in the n^(th) columnadjacent to the (n−1)^(th) column, in the different arrangementpatterns, so that the first number num11 to the fourth number num4 matchif possible, in comparison with the case in which the arrangement in thesame arrangement patterns as illustrated in FIG. 8 is performed.

[Configuration Example when the Image Sensor 2 is Formed as aSemiconductor Chip]

FIG. 19 is an overview diagram illustrating a configuration example whenthe image sensor 2 of FIG. 2 is formed as a semiconductor chip.

In other words, FIG. 19A is a plan view illustrating a configurationexample when the image sensor 2 is configured using one bare chip, andFIG. 19B is a perspective diagram illustrating a configuration examplewhen the image sensor 2 is configured using two bare chips stackedvertically.

When the image sensor 2 is configured using one bare chip, for example,a pixel array 10 may be formed on one bare chip, and circuit blocks 81A,81B and 81C in which the pixel driving unit 21, the column parallel ADconversion unit 22, the output unit 23, and circuits other than thepixel array 10 are included around the pixel array 10 are formed, asillustrated in FIG. 19A.

When the image sensor 2 is formed as a stack type image sensor using twobare chips stacked vertically, for example, the pixel array 10 may beformed in the upper chip stacked on an upper side of the two bare chips,and a circuit block 82 in which the pixel driving unit 21, the columnparallel AD conversion unit 22, the output unit 23, and circuits otherthan the pixel array 10 are included may be formed in the lower chipstacked on a lower side, as illustrated in FIG. 19B.

When the image sensor 2 is configured as the stack type image sensor asillustrated in FIG. 19B, in other words, when the image sensor 2 isconfigured using the upper chip in which the pixel array 10 is formedand the lower chip in which the circuit block 82 is formed as the twobare chips stacked vertically, it may be necessary to form the lowerchip to have the same size as the upper chip.

The upper chip, in which the pixel array 10 is formed, may be formed tohave the same size as the pixel array 10 formed on the one bare chip ofFIG. 19A. When the lower chip is formed to have the same size as theupper chip, it is necessary to form all of the circuits included in thecircuit blocks 81A to 83C of FIG. 19A as the circuit block 82 in thelower chip formed to have the same size as the upper chip.

Accordingly, it is necessary to further miniaturize the circuit of thecolumn parallel AD conversion unit 22 or the like included in thecircuit block 82. For example, for the column parallel AD conversionunit 22, it is necessary to make a distance between adjacent columns (acolumn pitch) shorter than that in the case in which the image sensor 2is configured using one bare chip, which is illustrated in FIG. 19A.

In such a case, when the first division FETs into which FET#A_(n−1) hasbeen divided and the second division FETs into which FET#B_(n−1) hasbeen divided, which constitute the differential pair of the (n−1)^(th)column, and the first division FETs into which FET#A_(n) has beendivided and the second division FETs into which FET#B_(n) has beendivided, which constitute the differential pair of the n^(th) columnadjacent to the (n−1)^(th) column, are arranged in the same arrangementpattern as illustrated in FIG. 8, the crosstalk characteristic of thecolumn parallel AD conversion unit 22 greatly deteriorates.

According to the present technology, the crosstalk characteristic can beimproved without a side effect. The present technology is particularlyuseful, for example, when the column pitch is short as illustrated inFIG. 19B.

[Method of Manufacturing the Image Sensor 2]

FIG. 20 is a flowchart illustrating a method of manufacturing asemiconductor chip as the image sensor 2, and particularly, a method ofmanufacturing the column parallel AD conversion unit 22.

In step S11, in the column parallel AD conversion unit 22, the firstdivision FETs into which FET#A constituting the differential pair hasbeen divided and the second division FETs into which FET#B has beendivided in the column area of an odd column are formed on a bare chip sothat an arrangement pattern of the division FETs becomes a firstarrangement pattern, and the first division FETs and the second divisionFETs in the column area of an even column are formed so that anarrangement pattern of the division FETs becomes a second arrangementpattern different from the first arrangement pattern.

Here, the first arrangement pattern and the second arrangement patternare determined so that the first number num11 to the fourth number num4are equal (if possible).

Further, currently, for a stack type image sensor, FET#A and FET#Bconstituting the differential pair of the column parallel AD conversionunit 22 are each divided into 10 or more first division FETs and 10 ormore second division FETs, the numbers of which are equal.

Further, for the 10 or more first division FETs and the 10 or moresecond division FETs, there are a large number of combinations ascombinations of the first arrangement pattern and the second arrangementpattern in which the first number num11 to the fourth number num4 areequal (if possible).

For example, the combination that provides the most excellent crosstalkcharacteristic of the column parallel AD conversion unit 22 may beadopted from among such combinations of the first arrangement patternand the second arrangement pattern.

Further, technology for reversing polarities of connections on an inputside of a comparator constituting a reference signal comparison-type ADCof a column parallel AD conversion unit every other column is disclosedin Japanese Patent No. 4640507.

According to the technology disclosed in Japanese Patent No 4640507, forexample, for a comparator in an even column, a reference signal s1 isinput to an inversion input terminal (−) and an electrical signal s2output by a pixel is input to a non-inversion input terminal (+), andfor a comparator in an odd column, the electronic signal s2 output bythe pixel is input to an inversion input terminal (−) and the referencesignal s1 is input to a non-inversion input terminal (+), therebypreventing degradation of image quality due to lateral stripes calledstreaking from occurring in a uniform texture area of an image.

However, in the technology disclosed in Japanese Patent No. 4640507, itis difficult to improve a crosstalk of the column parallel AD conversionunit since first division FETs and second division FETs into which eachof two FETs constituting a differential pair has been divided are notarranged in different arrangement patterns in two adjacent columns.

In other words, the present technology is completely different from thetechnology disclosed in a specification of Japanese Patent No. 4640507in that, in the present technology, the first division FETs and thesecond division FETs into which two of FET#A_(n) and FET#B_(n)constituting the differential pair have been divided are arranged indifferent arrangement patterns in two adjacent columns, whereas in thetechnology disclosed in the specification of Japanese Patent No.4640507, the polarities of connections on the input side of thecomparator of the column parallel AD conversion unit are reversed everyother column.

Further, since the technology disclosed in the specification of JapanesePatent No. 4640507 is not technology affecting the present technology,it may be used together with the present technology.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

In other words, the present technology may be applied to a solid-stateimaging device having an image sensor that receives radiation or otherelectromagnetic waves and outputs a corresponding electrical signal, aswell as to the image sensor 2 that is a solid-state imaging device thatcaptures an image.

Further, in the present embodiment, in the column parallel AD conversionunit 22, one ADC 31 is provided for one column of the pixel 11 _(m,n) ofthe pixel array 10. However, in the column parallel AD conversion unit22, for example, one ADC may be provided for a plurality of columns suchas two columns of the pixel 11 _(m,n) of the pixel array 10 and mayAD-convert an electrical signal from the two columns of the pixel 11_(m,n) in time division.

Further, in the present technology, in the adjacent (n−1)^(th) andn^(th) columns, the first division FETs and the second division FETs inthe (n−1)^(th) column and the first division FETs and the seconddivision FETs in the n^(th) column are necessarily arranged in differentarrangement patterns, and the arrangement patterns of the first divisionFETs and the second division FETs in each set of two columns of everyone column, such as a set of (n−1)^(th) column and (n+1)^(th) column anda set of n^(th) column and (n+2)^(th) column, may be the same and may bedifferent.

Additionally, the present technology may also be configured as below.

[1]A solid-state imaging device including:

an imaging unit including a plurality of image sensors; and

an analog to digital (AD) conversion unit including a plurality of ADconverters arranged in a row direction, each AD converter performing ADconversion of an electrical signal output by the image sensor,

wherein each of the AD converters includes a comparator having adifferential pair at an input stage, the differential pair including afirst transistor and a second transistor,

wherein the first and second transistors are each divided into an equalnumber of a plurality of division transistors, and

wherein an arrangement pattern of the plurality of division transistorsconstituting the comparator in a predetermined column and an arrangementpattern of the plurality of division transistors constituting thecomparator in an adjacent column adjacent to the predetermined columnare different from each other.

[2]The solid-state imaging device according to [1],

wherein the AD converter performs the AD conversion of the electricalsignal by comparing, in the comparator, a predetermined reference signalwith the electrical signal output by the image sensor.

[3]The solid-state imaging device according to [2],

wherein the reference signal is a signal whose level is changed overtime, and

wherein the AD converter further includes a counter that counts a timenecessary for a change of the level of the reference signal until levelsof the reference signal and the electrical signal output by the imagesensor match.

The solid-state imaging device according to any one of [1] to [3],

wherein the first and second transistors are each divided into an evennumber of division transistors.

[5]The solid-state imaging device according to any one of [1] to [4],

wherein the first division transistors and the second divisiontransistors are arranged in each of the predetermined column and theadjacent column so that parasitic capacitance coupling between the firsttransistor in the predetermined column and each of the first transistorand the second transistor in the adjacent column is created, andparasitic capacitance coupling between the second transistor in thepredetermined column and each of the first transistor and the secondtransistor in the adjacent column is created.

[6]The solid-state imaging device according to any one of [1] to [4],

wherein, in each of the predetermined column and the adjacent column,the first division transistors and the second division transistors arearranged so that the number of the first division transistors into whichthe first transistor in the predetermined column has been divided andthe first division transistors in the adjacent column that face eachother, the number of the second division transistors into which thesecond transistor in the predetermined column has been divided and thesecond division transistors in the adjacent column that face each other,the number of the first division transistors in the predetermined columnand the second division transistors in the adjacent column that faceeach other, and the number of the second division transistors in thepredetermined column and the first division transistors in the adjacentcolumn that face each other are all equal.

[7]The solid-state imaging device according to any one of [1] to [6],

wherein the solid-state imaging device includes two bare chips stackedvertically,

wherein the imaging unit is included in an upper chip stacked on anupper side of the two bare chips, and

wherein the AD conversion unit is included in an lower chip stacked on alower side of the two bare chips.

[8]A method of manufacturing a solid-state imaging device including animaging unit including a plurality of image sensors, and an analog todigital (AD) conversion unit including a plurality of AD convertersarranged in a row direction, each AD converter performing AD conversionof an electrical signal output by the image sensor, the methodincluding:

including, in each of the AD converters, a comparator having adifferential pair at an input stage, the differential pair including afirst transistor and a second transistor;

dividing the first and second transistors each into an equal number of aplurality of division transistors; and

arranging the plurality of division transistors constituting thecomparator in a predetermined column and the plurality of divisiontransistors constituting the comparator in an adjacent column adjacentto the predetermined column in different arrangement patterns.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2012-161998 filed in theJapan Patent Office on Jul. 20, 2012, the entire content of which ishereby incorporated by reference.

What is claimed is:
 1. A solid-state imaging device comprising: animaging unit including a plurality of image sensors; and an analog todigital (AD) conversion unit including a plurality of AD convertersarranged in a row direction, each AD converter performing AD conversionof an electrical signal output by the image sensor, wherein each of theAD converters includes a comparator having a differential pair at aninput stage, the differential pair including a first transistor and asecond transistor, wherein the first and second transistors are eachdivided into an equal number of a plurality of division transistors, andwherein an arrangement pattern of the plurality of division transistorsconstituting the comparator in a predetermined column and an arrangementpattern of the plurality of division transistors constituting thecomparator in an adjacent column adjacent to the predetermined columnare different from each other.
 2. The solid-state imaging deviceaccording to claim 1, wherein the AD converter performs the ADconversion of the electrical signal by comparing, in the comparator, apredetermined reference signal with the electrical signal output by theimage sensor.
 3. The solid-state imaging device according to claim 2,wherein the reference signal is a signal whose level is changed overtime, and wherein the AD converter further includes a counter thatcounts a time necessary for a change of the level of the referencesignal until levels of the reference signal and the electrical signaloutput by the image sensor match.
 4. The solid-state imaging deviceaccording to claim 3, wherein the first and second transistors are eachdivided into an even number of division transistors.
 5. The solid-stateimaging device according to claim 4, wherein the first divisiontransistors and the second division transistors are arranged in each ofthe predetermined column and the adjacent column so that parasiticcapacitance coupling between the first transistor in the predeterminedcolumn and each of the first transistor and the second transistor in theadjacent column is created, and parasitic capacitance coupling betweenthe second transistor in the predetermined column and each of the firsttransistor and the second transistor in the adjacent column is created.6. The solid-state imaging device according to claim 5, wherein, in eachof the predetermined column and the adjacent column, the first divisiontransistors and the second division transistors are arranged so that thenumber of the first division transistors into which the first transistorin the predetermined column has been divided and the first divisiontransistors in the adjacent column that face each other, the number ofthe second division transistors into which the second transistor in thepredetermined column has been divided and the second divisiontransistors in the adjacent column that face each other, the number ofthe first division transistors in the predetermined column and thesecond division transistors in the adjacent column that face each other,and the number of the second division transistors in the predeterminedcolumn and the first division transistors in the adjacent column thatface each other are all equal.
 7. The solid-state imaging deviceaccording to claim 6, wherein the solid-state imaging device includestwo bare chips stacked vertically, wherein the imaging unit is includedin an upper chip stacked on an upper side of the two bare chips, andwherein the AD conversion unit is included in an lower chip stacked on alower side of the two bare chips.
 8. A method of manufacturing asolid-state imaging device including an imaging unit including aplurality of image sensors, and an analog to digital (AD) conversionunit including a plurality of AD converters arranged in a row direction,each AD converter performing AD conversion of an electrical signaloutput by the image sensor, the method comprising: including, in each ofthe AD converters, a comparator having a differential pair at an inputstage, the differential pair including a first transistor and a secondtransistor; dividing the first and second transistors each into an equalnumber of a plurality of division transistors; and arranging theplurality of division transistors constituting the comparator in apredetermined column and the plurality of division transistorsconstituting the comparator in an adjacent column adjacent to thepredetermined column in different arrangement patterns.